# Mysteries of the Unknown

Mysteries of the Unknown is a series of books about the paranormal, published on the North-American home market by Time-Life Books from 1987 through 1992. Each book focused on a different topic, such as ghosts, UFOs, psychic powers and dreams. Book titles included The UFO Phenomenon, Witches and Witchcraft, Hauntings, and more. According to the LinkedIn page of Tom Corry, Time-Life's then-Vice President of Product Management (1984–90) and under whose auspices the series was launched, it was "the largest selling book series Time-Life ever produced."

## Genesis

The idea for the series was conceived after the publisher's management took note of the popularity in the home market of its preceding Enchanted World myths and folklore book series. A polling of its customer database revealed that there was a "decent interest" among customers in having a more mysterious and metaphysical book series as well, according to Tom Corry. Not only that, but the publisher also played into the era's growing popular fascination with the para- or supernatural, which eventually culminated in the long-running and hugely successful 1993-2000 X-Files television series and the many motion picture emulators it spawned afterwards. Corry recalled that management "thought we could probably squeeze a series out of this," and went ahead with the development of the series.
The Enchanted World series had already set in motion Time-Life Books' trend towards more sensationalism away from the hitherto soberly and scientifically written publications, the publisher was until then renowned for. Mysteries of the Unknown though, took it up a notch and the actual "The Editors of Time-Life Books" content writers/creators resented their management for it, or as Corry had put it, "Oh yeah. They hated that stuff." At first the editorial staff seemed to be justified in their skepticism as initial sales were less than stellar when the series was launched in the early summer of 1987, until happenstance intervened. On 16–17 August 1987 the Harmonic Convergence event took place which sparked a massive upsurge in worldwide interest in the topics covered by the Time-Life series, and sales took off with Corry recalling that "[r]ight after that, in the fall of '87, we couldn't print enough books." As for the skeptical editors and despite them having never embraced the subject matter, Corry did credit them for their usual steadfast adherence of subjecting the series to the same rigors of investigation and annotation as any of their historical titles, resulting in that the Mysteries of the Unknown series also employed the same basic scientific principles in genuine attempts to validate the credibility of the theories discussed within. The book series broke the sales record for the company, which enabled the New York Times to report that one year into its release 700,000 copies of the first, "Mystic Places", volume had already been sold on the home market alone, whilst being just one of the eventual 33-volume series, and without even taken into account the additional sales in international markets.

## Release overview

Each volume in the 33-volume series, including the "Master Index", was either 144 or 160 pages in length (the 176-page volume 11 excepted), heavily illustrated and with pictorial essays on specific topics within each volume and were as a rule issued without a dust jacket. Executed in hardcover, each volume was bound in black faux leatherette, the cover endowed in silver printed text imprints, and with a square shaped illustration glued on.
Time-Life Books was renowned for its exclusive use of the direct-to-consumer (DTC) business model, meaning they sold their book series directly to customers and mailed the individual books to households on a (bi-)monthly basis, typically through subscription, and the Mysteries of the Unknown series was no exception. As usual, the book series was supported by a television ad campaign, which was particularly vigorous in this case (see below). By 1991 however, Time-Life Books' DTC business model had started to slump, and the company decided to distribute their publications through regular bookstore retail channels as well alongside their hitherto traditional DTC-only channel, such as the Barnes & Noble bookstores. It resulted for the time being in a decided recovery of the company's overall book sales which went a long way to explain the long-lived availability of Mysteries of the Unknown series well into the late 1990s.
As had been customary with the Time-Life Books series publications, each of the original US first-print series volumes had received two ISBNs (the second one usually eight numbers higher), with the lower number indicating the retail/DTC copies whereas the higher ones indicate the library binding ("lib. bdg.") copies as specified in the book colophons – which remained adhered to for later with higher newly assigned ISBNs endowed revised editions as well, if there were any. Neither of the two versions nor their later reprints were furnished with dust jackets. However, in 1997 a separate printing was commissioned by Barnes & Noble as retail exclusives for their bookstore chain, and while these were otherwise nearly indistinguishable from the main home market releases, safe for the copyright colophons, they were endowed with dust jackets. It is unknown however, what the extent of the Barnes & Noble reprint run was beyond the two known titles listed below.
An out-of-the-ordinary home market release concerned the Chinese-language versions Time-Life Books started to issue a year earlier in North America on behalf of the Chinese-speaking populace. As with the Barnes & Noble edition and already rare to begin with, it is hard to ascertain the scope of this release beyond the six known titles listed below.

### International editions

Contrary to the inspirational Enchanted World series, which had not been widely translated into other languages, its Mysteries of the Unknown spawn was. UK as well as French, German, and Dutch-language editions are known to have been released in the overlapping time-span by the local "Time-Life Books B.V." Amsterdam subsidiary branch as otherwise exact copies of their US counterparts where book format execution was concerned. The 1990-93 Netherlands/Flanders Dutch-language edition though, was not only published out-of-order, but severely truncated as well, as only eight titles are known to have been released in translation, most likely because of disappointing sales. The 1988-93 UK, French (as Mystères de l'inconnu, also disseminated in the other Francophone countries, French-Canada included) and German (as Geheimnisse des Unbekannten, also disseminated in the other Germanophone countries) editions on the other hand, were released in their entirety, albeit that volume 33, the "Master Index", was passed over in all cases. The UK edition also served for the series' dissemination in the Commonwealth of Nations, Anglophone Canada excepted which was served with the US home market edition. Wile the French edition did not, the German edition carried Dutch ISBNs, confusingly the very same ones as the Dutch-language counterparts, save volume 12, if there had been any. Contrary to the French and Dutch editions though, which only saw one print run each, yet like in the US, the series was a popular one in the UK and the German-speaking territories in particular, enjoying multiple reprints; of the first German-language title, "Mystische Stätten" (="Mystic Places"), for example, is known that there have been at least nine Time-Life Books printings between 1988 and 1992 alone. Except for the Dutch-language edition, which took considerably longer, the other Time-Life European edition releases lagged about six to twelve months behind the release of the North-American source publications. This also held true for the UK edition, as additional editorial work was required to convert the texts from American-spelled English into British-spelled English.
The Amsterdam subsidiary maintained administrative satellite offices in the UK, Germany and France which facilitated the series publication by Time-Life Books themselves. In those European countries where Time-Life Books did not have a physical presence, another path was usually taken to market their publications; extending publication licenses to local publishers who showed interest in releasing the books in translation – interested parties in other language territories where no edition in translation was considered, were offered the opportunity to acquire the original English-language version via mail through their nearest Time-Life Books subsidiary as was standard operating procedure for the company at the time, typically by taking out a series subscription. Per the book colophons, these European licenses could have been extended by either the Amsterdam subsidiary, or, in rarer cases, by the American mother company as had been the case for the Spanish-language edition. Where Mysteries of the Unknown was concerned, interest turned out to be ample. Mediterranean Europe saw three editions in translation besides the French one. In Greece the series was partially released by Athens-based Alkyon Publications (as Παραψυχολογία, 1990–91, eleven known published volumes in dust jacket, but published out-of-order), Italy saw a likewise partial series release by Milan publishing giant Arnoldo Mondadori Editore (as I misteri dell'ignoto, 1990–92, the first twenty volumes published), whereas Time-Life Books' regular go-to licensee Ediciones Folio, S.A. from Barcelona had a Spanish-language edition published (as Misterios de lo desconocido, entire series published in 1993, the "Master Index" included)
Italy already saw a reissue of their series by Balsamo/Bresso-based Hobby & Work Italiana Editrice in 1995–96. Hobby & Work was actually predominantly a partwork publisher, a publication format particularly popular in southern Europe at the time, and not only reissued the series in the original hardback book format, but had each book split up in five magazine-style paperback parts as well, concurrently selling them as magazine issues through the newsstand channel with one of them accompanied by a 30-minute VHS-tape that dealt with the underlying topic. As a matter of fact, this also applied to the Spanish edition as Folio co-published the series with specialized Madrid partwork publisher Ediciones del Prado who had already marketed the newsstand variant of the publication in a similar way two years before Hobby & Work would do.
The Nordic countries too, received their share of the series in translation variants. Coined Mystikkens verden, the series saw a partial publication in Denmark and Norway, as with their southern neighbors in a book format copied from the source material. The Danish edition was released by Copenhagen publisher Lademann A/S [dk] (1990–93, 28 volumes), whereas the Norwegian edition was released by Oslo-based Gyldendal Norsk Forlag AS (1991–92, 12 volumes). Like the North-American volumes, the Danish and Norwegian counterparts were furnished with two ISBNs as it is customary in these countries to distinguish between books sold through magazine newsstand channels and books sold through the retail bookstore channel if both channels are selected by the publisher in question as means of distribution. Of volume 12 "Hauntings" at least, is known that it had also seen its "Sálfarir" Icelandic-language counterpart edition published in 1991 by Almenna bókafélagið [is], Reykjavík. It is unknown though, if this release concerned a standalone one-off, or if it had been part of a larger publication effort.
It was not just Europe that saw their own editions published; other parts of the world saw their region-specific editions released as well by local publishers under a full license from the Time-Life Books, Inc. mother company. The largest of these concerned the Brazilian Mistérios do desconhecido edition published by Abril Livros operating out of Rio de Janeiro (1992–96, 24 volumes), likewise in a format edition that was a Portuguese-language copy of the originating home market publication – a salient detail was that mother country Portugal had not seen its own edition released. The second known Latin-American edition was the 1992-93 Misterios de lo desconocido Spanish-language publication released in Argentina by Editorial Atlántida S.A., a major magazine publisher from Buenos Aires. Theirs however, was a deviant paperback release format with redesigned wrappers as cover, as the at least twelve known volumes were released in a magazine-type format under the overall Biblioteca Time Life Books Conozca Más moniker as indication that it was intended as a side collection of the publisher's then-main Conozca Más magazine publication. In service of that goal and published out of order, the volumes were also truncated to 98 pages. The precise extent of that publication effort is unknown however.
Rounding out the international other-language editions, are the ones known to have been released in the Far East, again under a full license from Time-Life Books, Inc. A partial series release in translation was published in one batch in mainland China in February 2002 by Lijiang Publishers, Guilin, as part of their "鏖战位置丛书 (Tiao zhan wei zhi cong shu)" collection. At least five such volume releases are known. A single Japanese-language release of volume 24 is also known to have been published by Tokyo-based Burai Shuppan in 2006. But as with the earlier referenced Icelandic release, it remains unclear whether or not it had been a standalone one-off, or if it had been part of a larger publication effort. The Far-Eastern releases though, concerned in both cases smaller-sized paperback budget-price releases with completely redesigned covers.
Over a decade after the publication of the series by Time-Life Books, some, but not all, of its first-edition UK and German-language volumes were joined by two followup editions released by third-party publishers, who were licensed to do so by the European "Time-Life Books B.V." Amsterdam branch as specified in the colophons of the individual volumes. The first concerned the 1999 second-edition German-language hardcovers without a dust jacket release, licensed to Eltville-based Predita Verlag who released these volumes under its "ECO Köln/VVA" imprint, featuring deviant cover art and newly assigned ISBNs, but did not carry the first edition Geheimnisse des Unbekannten series title though the original Time-Life cover illustration was printed on the back-cover. They were joined by a 2005-06 third German-language edition released by Augsburg-based publisher Weltbild Verlag [de]. Also executed as simple hardcovers with again new covers they were this time around issued with no ISBNs and subordinated under the publisher's "Weltbild-Sammler Editionen" collection, mentioning the original German series title as subtitle. Somewhat confusingly, as there was some overlap in volume titles reissued, Predita continued their second-edition release by reprinting some of its volumes under the same ISBN with redesigned versions of their covers around this time as well, but now under its "H+L Verlag, Köln" imprint. The German reiteration effort was rather modest in scope, as only about a dozen volumes of the series are known to be released by Predita under both its imprints, whereas that of Weltbild was even more modest with its eight known volumes released.
Apart from the two licensed German-language reiterations, some series volumes saw a 2003-04 second-edition in the UK as well from the London-based Caxton Publishing Group, likewise under a full license from the European Time-Life Books B.V. which had managed to stay in business a few years longer after the American "Time-Life Books, Inc." mother division had gone defunct in 2001 as a dedicated book publisher. The volumes released by Caxton featured redesigned cover art with a dust jacket and were furnished with new ISBNs. As usual with the Caxton editions, its licensed Time-Life pedigree releases did feature the Time-Life logo on the spine and front cover of the individual books. Had the German reiteration effort already been modest in scope, the UK effort turned out to be far more modest with its only three known second-edition title releases. Both the UK and German reiterations were specifically intended for the regular bookstore retail channel.
Contrary to the ubiquitous availability of the first edition Time-Life series volumes on the UK and German used-book markets (as they are on all other territory markets as well for that matter, the English-language ones in particular), their higher edition volumes are a lot more uncommon. Still, by becoming one of Time-Life's most widely disseminated series in translation, it was testament to the worldwide appeal and popularity (and thus financial success) the Mysteries of the Unknown series enjoyed at the time.

### Volume titles of Mysteries of the Unknown

In order of publication; the US, UK and German editions have their first (Time-Life) edition ISBN(s) listed first, followed by the higher edition ISBNs where applicable. Where listed, the US "076070..." ISBNs concern the 1997 editions in dust jacket for the Barnes & Noble retail bookstore chain. The US editions have both their (1st and revised edition) retail, and library binding ISBNs listed, whereas the Danish and Norwegian editions have both their retail, and magazine newsstand channel ISBNs listed where known.
* 01. "Mystic Places" (1987, ISBN 0809463121, 080946313X, 160 p.); Discusses places known for supernatural activity or ancient mysteries yet unsolved. Topics include the search for Atlantis, traveling to the Earth's center, the Great Pyramid of Giza, Stonehenge, and the Nazca lines.
** UK edition: "Mystic Places" (1988/03, ISBN 0705406679)
** French edition: "Les lieux énigmatiques" (1988, ISBN 273440415X)
** German edition: "Mystische Stätten" (1988, 1999, 2005, ISBN 9061829917, 3933468876, OCLC 76778095)
** Danish edition: "Mystiske steder" (1990, ISBN 8715085686)
** Italian edition: "I luoghi del mistero" (1990/09, 1994, OCLC tbd, ISBN 8871331761)
** Greek edition: "Μυστικιστικοί τόποι" (1990, OCLC 1182615658)
** Dutch edition: Mysterieuze plaatsen" (1991, ISBN 9061829917)
** Norwegian edition: "Mystiske steder" (1991, ISBN 8205193088, 8252520200)
** Spanish edition: "Lugares enigmáticos" (1993, ISBN 8478382453)
** Brazilian edition: "Lugares místicos" (1993, OCLC 51359853)
** Chinese edition: "神秘之地 (Shen mi zhi di)" (2002/02, ISBN 7540727799, 208-page paperback)
* 02. "Psychic Powers" (1987, ISBN 0809463083, 0809463091, 160 p.); Discusses ESP and other people who claim to possess psychic abilities. Includes information on Patience Worth and the involvement of psychics in the Yorkshire Ripper case.
** UK edition: "Psychic Powers" (1988/05, ISBN 0705406687)
** French edition: "Les pouvoirs de l'esprit" (1988, ISBN 2734404192)
** German edition: "Übersinnliche Kräfte" (1988, ISBN 9061829925)
** Danish edition: "Overnaturlige evner" (1990, ISBN 8715085724, 8715085805)
** Italian edition: "I poteri della mente" (1990/10, 1994, OCLC tbd, ISBN 8871331753)
** Greek edition: "Ψυχικές Δυνάμεις" (1991, no ISBN/OCLC issued/known)
** Norwegian edition: "Psykiske krefter" (1991, ISBN 8205193118, 8252520227)
** Spanish edition: "Poderes psíquicos" (1993, ISBN 8478382135)
** Brazilian edition: "Poderes da mente" (1994, no ISBN/OCLC issued/known)
** Argentinian edition: "Poderes parapsicológicos" (1992/09, no ISBN/OCLC issued/known)
* 03. "The UFO Phenomenon" (1987, 1997 ISBN 0809463245, 0809463253, 0760704392, 160 p.); Discusses sightings and controversies regarding unidentified flying objects. Topics include alien encounters, the Roswell incident, and allegations of government cover-ups.
** UK edition: "The UFO Phenomenon" (1988/08, 2004/10, ISBN 0705406695, 1844470032)
** French edition: "Le phénomène des OVNI" (1990, ISBN 2734404303)
** German edition: "Die UFOs" (1988, 1999, ISBN 9061829933, 3933468914)
** Danish edition: "Gæster fra rummet" (1990, ISBN 8715085694, 8715085805)
** Italian edition: "UFO ed Extraterrestri" (1990/11, 1994, OCLC 800865910, ISBN 8871331680)
** Greek edition: "Το φαινόμενο των UFO" (1990, OCLC 1182624388)
** Dutch edition: "Het UFO-mysterie" (1990, ISBN 9061829933)
** Norwegian edition: "UFO-fenomenet" (1991, ISBN 8205193266, 8252520251)
** Spanish edition: "El fenómeno OVNI" (1993, ISBN 847838216X)
** Brazilian edition: "O fenômeno OVNI" (1992, no ISBN/OCLC issued/known)
** Argentinian edition: "El fenómeno OVNI" (1992, no ISBN/OCLC issued/known, first Argentinian release)
** Chinese edition: "UFO 现象 (UFO xian xiang)" (2002/02, ISBN 7540727926, 214-page paperback)
* 04. "Psychic Voyages" (1987, ISBN 0809463164, 0809463172, 144 p.); Discusses accounts of out-of-body experiences, near-death experiences, and reincarnation.
** UK edition: "Psychic Voyages" (1988/09, ISBN 0705406709)
** French edition: "Voyages hors du corps" (1990, ISBN 2734404362)
** German edition: "Seelenreisen" (1989, 1999, ISBN 9061829941, 3933468906)
** Danish edition: "På rejse med sjælen" (1990, ISBN 8715085708, 8715085805)
** Italian edition: "I viaggi della mente" (1990/12, 1994, OCLC 801316658, ISBN 8871331745)
** Dutch edition: "Paranormale raadselen" (1991, ISBN 9061829941)
** Norwegian edition: "Sjelereiser" (1991, ISBN 8205193126, 8252520235)
** Spanish edition: "Viajes psíquicos" (1993, ISBN 8478382151)
** Brazilian edition: "Viagens psíquicas" (1993, no ISBN/OCLC issued/known)
** Argentinian edition: "La vida en el más allá" (1993/05, no ISBN/OCLC issued/known, last known Argentina release as numbered issue 12)
* 05. "Phantom Encounters" (1987, ISBN 0809463288, 0809463296, 144 p.); Discuses encounters with mysteries apparitions. Includes stories of haunted families, banishing ghosts, and various ghost stories from Japan.
** UK edition: "Phantom Encounters" (1988/11, ISBN 0705406717)
** French edition: "Fantômes et apparitions" (1988, ISBN 2734404427)
** German edition: "Unerklärliche Begegnungen" (1988, 1999, 2005, ISBN 906182995X, 3933468930, EAN 4029872020035)
** Danish edition: "Spøgelser og genfærd" (1990, ISBN 8715085716, 8715085805)
** Italian edition: "I fantasmi" (1990, 1994, OCLC 801316632, ISBN 8871331737)
** Norwegian edition: "Spøkelser og gjenferd" (1991, ISBN 8205202443, 8252520669)
** Spanish edition: "Encuentros con fantasmas" (1993, ISBN 8478382119)
** Brazilian edition: "Encontros espectrais" (1992, no ISBN/OCLC issued/known)
* 06. "Visions and Prophecies" (1988, ISBN 0809463202, 0809463210, 160 p.)
** UK edition: "Visions and Prophecies" (1989/02, ISBN 0705406725)
** French edition: "Visions et prophéties" (1993, ISBN 2734404451)
** German edition: "Visionen und Utopien" (1991, 1999, 2005, ISBN 9061821592, 3933468957, OCLC 433055963)
** Danish edition: "Profetier og syner" (1991, ISBN 8715085759, 8715085805)
** Italian edition: "Visione e profezie" (1991/02, 1994, OCLC 955022605, the 1994 reissue lacks an ISBN)
** Greek edition: "Οράματα και προφητείες" (1990, OCLC 1182617814)
** Norwegian edition: "Visjoner og profetier" (1991, ISBN 8205202451, 8252520642)
** Spanish edition: "Adivinaciones y profecías" (1993, ISBN 8478382143)
** Brazilian edition: "Visões e profecias" (1992, no ISBN/OCLC issued/known)
** Argentinian edition: "Visiones y profecías" (1992/09, no ISBN/OCLC issued/known)
* 07. "Mysterious Creatures" (1988, ISBN 0809463326, 0809463334, 144 p.); Discusses cryptozoology, focusing on sea monsters and ape-men. Topics include Nessie, the Patterson–Gimlin film, Ameranthropoides loysi, and mokele-mbembe.
** UK edition: "Mysterious Creatures" (1989/03, ISBN 0705406733)
** French edition: "Monstres de légende" (1989, ISBN 2734404567)
** German edition: "Rätselhafte Wesen" (1989, 1999, ISBN 9061829976, 3933468892)
** Danish edition: "Mærkelige væsener" (1991, ISBN 8715085732, 8715085805)
** Italian edition: "Creature leggendarie" (1991/03, 1994, OCLC 955022605, ISBN 8871331710)
** Greek edition: "Μυστηριώδη όντα" (1990, OCLC 1182616935)
** Dutch edition: "Mysterieuze wezens" (1991, ISBN 9061829976)
** Norwegian edition: "Mystiske skapninger" (1992, ISBN 8205202486, 8252520677)
** Spanish edition: "Criaturas misteriosas" (1989, ISBN 8478382240)
** Brazilian edition: "Criaturas misteriosas" (1996, no ISBN/OCLC issued/known)
** Chinese edition: "神秘的生物 (Shen mi de sheng wu)" (1999, ISBN 0809465574, US publication for Chinese-speaking citizenry)
** Chinese edition: "神秘的生物 (Shen mi de sheng wu)" (2002/02, ISBN 7540727802, 186-page paperback)
* 08. "Mind Over Matter" (1988, ISBN 0809463369, 0809463377, 144 p.); Deals predominantly with people with abilities considered abnormal, though not necessarily supernatural. Discusses hypnosis, poltergeists, levitation and Uri Geller.
** UK edition: "Mind Over Matter" (1989/05, 2004/10, ISBN 0705406741, 1844470016)
** French edition: "La force du psychisme" (1989, ISBN 273440463X)
** German edition: "Geist über Materie" (1989, ISBN 9061829984)
** Danish edition: "Ånd over materie" (1991, ISBN 8715088421, 8715085805)
** Italian edition: "Spirito e materia" (1991/04, 1994, OCLC 955022605, ISBN 8871331702)
** Greek edition: "Η Δύναμη του Νου" (1990, no ISBN/OCLC issued/known)
** Norwegian edition: "Åndskraft mot materie" (1991, ISBN 8205193096, 8252520219)
** Spanish edition: "Mente sobre materia" (1993, ISBN 8478382208)
** Brazilian edition: "A mente domina a matéria" (1995, no ISBN/OCLC issued/known)
** Argentinian edition: "Los increíbles poderes de la mente" (1993/02, no ISBN/OCLC issued/known)
** Chinese edition: "精神支配物質 (Jing shen zhi pei wu zhi)" (1996, ISBN 0783555520, US publication for Chinese-speaking citizenry)
* 09. "Cosmic Connections" (1988, ISBN 0809463407, 0809463415, 160 p.); Discusses humankind's long curiosity about the influence of celestial bodies. It includes extensive looks at the solar system and the zodiac.
** UK edition: "Cosmic Connections" (1989/07, ISBN 070540675X)
** French edition: "Les influences astrales" (1989, ISBN 2734404826)
** German edition: "Die Astrologie" (1989, ISBN 9061829992)
** Danish edition: "Astrologi" (1991, ISBN 8715085740, 8715085805)
** Italian edition: "Le influenze astrali" (1991/05, 1994, OCLC tbd, ISBN 8871331699)
** Greek edition: "Η Δύναμη του Νου" (1990, no ISBN/OCLC issued/known)
** Dutch edition "Astrologie" (1992 ISBN 9061829992)
** Norwegian edition: "Astrologi" (1992, ISBN 8205202478, 8252520650)
** Spanish edition: "Contactos cósmicos" (1993, ISBN 8478382127)
** Brazilian edition: "Conexões cósmicas" (1997, no ISBN/OCLC issued/known)
** Chinese edition: "星辰與命運 (Xing chen yu ming yun)" (1996, ISBN 0783555504, US publication for Chinese-speaking citizenry)
* 10. "Spirit Summonings" (1988, ISBN 080946344X, 0809463458, 160 p.); Discusses mediums and seances. Topics include the Fox sisters, Daniel Dunglas Home, and Harry Houdini's debunking of mediums.
** UK edition: "Spirit Summonings" (1989/09, ISBN 0705406768)
** French edition: "L'invocation des esprits" (1989, ISBN 2734404974)
** German edition: "Spiritismus" (1989, ISBN 9061821568)
** Danish edition: "De døde lever" (1991, ISBN 8715085783, 8715085805)
** Italian edition: "L'evocazione degli spiriti" (1991/06, 1994, OCLC tbd, ISBN 8871331729)
** Dutch edition "Spiritisme" (1992 ISBN 9061821568)
** Norwegian edition: "Kontakt med åndeverdenen" (1992, ISBN 8205202494, 8252520685)
** Spanish edition: "Conjuros de espíritos" (1993, ISBN 8478382283, one of the very few first editions to feature a variant cover illustration)
** Brazilian edition: "Evocação dos espíritos" (1996, OCLC 51373742)
* 11. "Ancient Wisdom and Secret Sects" (1989, ISBN 0809463482, 0809463490, 176 p.); Includes details on Hermeticism and secret societies.
** UK edition: "Ancient Wisdom and Secret Sects" (1989/11, ISBN 0705406776)
** French edition: "Les sociétés secrètes" (1989, ISBN 2734405075)
** German edition: "Überlieferte Weisheiten und Geheime Gesellschaften" (1989, ISBN 9061821576)
** Danish edition: "Hemmelige selskaber" (1991, ISBN 8715085805, 8715085767)
** Italian edition: "Le Sette segrete" (1991/07, 1995, 1998, OCLC tbd, ISBN 8871331672, 8871332903)
** Greek edition: "Αρχαια σοφια και μυστικες λατρειες" (1990, no ISBN/OCLC issued/known)
** Spanish edition: "Sabidurias milenarias y sectas secretas" (1989, ISBN 8478382186)
** Brazilian edition: "Seitas secretas" (1996, no ISBN/OCLC issued/known)
* 12. "Hauntings" (1989, 1997, ISBN 0809463520, 0809463539, 0760706476, 144 p.); Discusses the apparent haunting of people and places by ghosts and ghosting hunting. Includes information on poltergeists, the Moberly–Jourdain incident, ghost ships and the Bell witch.
** UK edition: "Hauntings" (1990/02, ISBN 0705406784)
** French edition: "Les lieux hantés" (1989, ISBN 2734405164)
** German edition: "Geisterphänomene" (1989, 1999, ISBN 9061821584, 393346885X)
** Danish edition: "Hjemsøgte steder" (1991, ISBN 8715085775, 8715085805)
** Italian edition: "I luoghi visitati" (1991, 1995, OCLC tbd, ISBN 8871331664)
** Dutch edition "Spoken en geesten" (1993, ISBN 9053900039, final Dutch-language series release and the only one not sharing its ISBN with the German-language edition)
** Greek edition: "Φαντάσματα" (1991, no ISBN/OCLC issued/known)
** Norwegian edition: "Hjemsøkte steder" (1991, ISBN 8205193274, 8252520243)
** Spanish edition: "Encantamientos" (1993, ISBN 8478382224)
** Brazilian edition: "Assombrações" (1995, no ISBN/OCLC issued/known)
** Icelandic edition: "Sálfarir" (1991, ISBN 9979400145)
* 13. "Powers of Healing" (1989, 1990 revised, ISBN 0809463563, 0809463571, 0809463687, 0809463695, 144 p.); Discusses unexplained alternatives to traditional medicine. Topics include medicine men, Edgar Cayce, acupuncture, Rasputin and chakras.
** UK edition: "Powers of Healing" (1990/04, ISBN 0705406792)
** French edition: "Le don de guérir" (1989, ISBN 273440527X)
** German edition: "Heilende Kräfte" (1990, 2006, ISBN 9061821878, OCLC 218655620)
** Danish edition: "Healing" (1991, ISBN 8715085791, 8715085805)
** Italian edition: "I guaritori" (1991/09, 1995, OCLC tbd, ISBN 8871332040)
** Spanish edition: "Poderes curativos" (1993, ISBN 8478382194)
** Brazilian edition: "Poderes de cura" (1995, no ISBN/OCLC issued/known)
* 14. "Search for the Soul" (1989, 1990 revised, ISBN 0809463601, 080946361X, 0809463849, 0809463857, 144 p.)
** UK edition: "Search for the Soul" (1990/06, ISBN 0705406865)
** French edition: "A la recherche de l'âme" (1990, ISBN 273440530X)
** German edition: "Die Suche nach der Seele" (1990, ISBN 9061821975)
** Danish edition: "På jagt efter sjælen" (1992, ISBN 8715088448, 8715085805)
** Italian edition: "Alla ricerca dell'anima" (1991/10, 1995, OCLC tbd, ISBN 8871332040)
** Greek edition: "Έρευνες για την Ψυχή" (1990, no ISBN/OCLC issued/known)
** Spanish edition: "La búsqueda de alma" (1993, ISBN 8478382313)
** Brazilian edition: "Poderes de cura" (1995, no ISBN/OCLC issued/known)
* 15. "Transformations" (1989, ISBN 0809463644, 0809463652, 144 p.); Discusses human transformation into animals or other supernatural creatures. Focuses on werewolves and vampires. Topics include tricksters, feral children, Peter Stubbe and Elizabeth Báthory.
** UK edition: "Transformations" (1990/10, ISBN 0705406873)
** French edition: "Les métamorphoses" (1990, ISBN 2734405350)
** German edition: "Wesensverwandlungen" (1990, ISBN 906182186X)
** Danish edition: "Forvandlinger" (1992, ISBN 8715088456, 8715085805)
** Italian edition: "Le metamorfosi" (1991/11, 1995, OCLC tbd, ISBN 8871332075)
** Greek edition: "Μεταμορφώσεις" (1991, no ISBN/OCLC issued/known, last known Greek-language series release)
** Spanish edition: "Metamorfosis" (1989, ISBN 8478382119)
* 16. "Dreams and Dreaming" (1990, ISBN 0809463881, 080946389X, 160 p.)
** UK edition: "Dreams and Dreaming" (1990/09, ISBN 0705406881)
** French edition: "L'expérience du rêve" (1990, ISBN 2734405466)
** German edition: "Traum und Traumdeutung" (1990, ISBN 9061821983)
** Danish edition: "Drømme og drømmetydning" (1992, ISBN 8715088464, 8715085805)
** Italian edition: "I sogni" (1991/12, 1995, OCLC tbd, ISBN 8871332083)
** Spanish edition: "Sueños y fantasías" (1993, ISBN 8478382399)
** Brazilian edition: "No mundo dos sonhos" (1992, no ISBN/OCLC issued/known)
** Argentinian edition: "El mensaje de los sueños" (1992/12, no ISBN/OCLC issued/known)
** Chinese edition: "梦与做梦 (Meng yu zuo meng)" (2002, ISBN 7540727934, 186-page paperback)
* 17. "Witches and Witchcraft" (1990, ISBN 080946392X, 0809463938, 144 p.)
** UK edition: "Witches and Witchcraft" (1990, ISBN tbd)
** French edition: "Magie et sorcellerie" (1990, ISBN 2734405520)
** German edition: "Hexen und Hexenwahn" (1990, 1999, ISBN 9061821991, 3933468868)
** Danish edition: "Hekse og heksetro" (1992, ISBN 8715088472, 8715085805)
** Italian edition: "Magia e stregoneria" (1992/01, 1995, OCLC tbd, ISBN 8871332091)
** Spanish edition: "Brujas y brujería" (1993, ISBN 847838233X)
** Brazilian edition: "Bruxas e bruxarias" (1995, no ISBN/OCLC issued/known)
** Argentinian edition: "El mundo oculto de las brujas" (1993/04, no ISBN/OCLC issued/known)
* 18. "Time and Space" (1990, ISBN 0809463962, 0809463970, 144 p.); Deals predominantly with the history of human interpretations of time and space, as well as unusual phenomena associated with the two (such as time slips). Quantum physics and Pythagorean mysticism are discussed at length.
** UK edition: "Time and Space" (1991/02, ISBN 070540692X)
** French edition: "La quatrième dimension" (1990, ISBN 2734405601)
** German edition: "Raum und Zeit" (1990, 2005, ISBN 9061822009, OCLC 163425277)
** Danish edition: "Tid og rum" (1992, ISBN 8715088480, 8715085805)
** Italian edition: "La quarta dimensione" (1992/02, 1996, OCLC tbd, ISBN 8871332105)
** Norwegian edition: "Tid og rom" (1992, ISBN 8205202508, 8252520693, final Norwegian-language series release)
** Spanish edition: "Tiempo y espacio" (1993, ISBN 8478382259)
** Brazilian edition: "Tempo e espaço" (1995, no ISBN/OCLC issued/known)
** Chinese edition: "时间与空间 (Shi jian yu kong jian)" (1999, ISBN 080946554X, US publication for Chinese-speaking citizenry)
* 19. "Magical Arts" (1990, ISBN 0809463806, 0809463814, 144 p.)
** UK edition: "Magical Arts" (1991/03, ISBN 0705406911)
** French edition: "Magie et sciences occultes" (1991, ISBN 2734405679)
** German edition: "Die magischen Künste" (1991, 2005, ISBN 9061821967, OCLC 163425277)
** Danish edition: "Magiens kraft" (1993, ISBN 8715085805)
** Italian edition: "Gli incantesimi" (1992/03, 1996, OCLC tbd, ISBN 8871332113)
** Spanish edition: "Artes mágicas" (1993, ISBN tbd)
* 20. "Utopian Visions" (1990, ISBN 0809463768, 0809463776, 160 p.)
** UK edition: "Utopian Visions" (1991/05, ISBN 0705406903)
** French edition: "Visions utopiques" (1991, ISBN 2734405741)
** German edition: "Visionen und Utopien" (1991, 1999, 2005, ISBN 9061821592, 3933468957, OCLC 433055963)
** Danish edition: "Drømmen om Utopia" (1992, ISBN 8715088499, 8715085805)
** Italian edition: "Il mondo dell'utopia" (1992/04, 1996, OCLC tbd, ISBN 8871332121, final Italian-language series release)
** Spanish edition: "Visiones utópicas" (1993, ISBN 8478382402)
* 21. "Secrets of the Alchemists" (1990, ISBN 0809465000, 0809465019, 144 p.)
** UK edition: "Secrets of the Alchemists" (1991/07, ISBN 0705406938)
** French edition: "Les secrets des alchimistes" (1991, ISBN 2734405814)
** German edition: "Die Alchimisten" (1991, ISBN 9061822173)
** Danish edition: "Alkymisternes hemmeligheder" (1992, ISBN 8715085805)
** Spanish edition: "Secretos de los alquimistas" (1993, ISBN 8478382321)
** Brazilian edition: "Segredos dos Alquimistas" (1996, no ISBN/OCLC issued/known)
* 22. "Eastern Mysteries" (1990, ISBN 0809465043, 0809465051, 160 p.)
** UK edition: "Eastern Mysteries" (1991/10, ISBN 0705406946)
** French edition: "Le mysticisme oriental" (1991, ISBN 2734405881)
** German edition: "Fernöstliche Weisheiten" (1991, ISBN 9061822181)
** Danish edition: "Østens mystik" (1993, ISBN 8715085805)
** Spanish edition: "Misterios orientales" (1993, ISBN 8478382372)
** Brazilian edition: "Mistérios orientais" (1996, no ISBN/OCLC issued/known)
** Chinese edition: "東方的神秘 (Dong fang de shen mi)" (1996, ISBN 0783555555, US publication for Chinese-speaking citizenry)
* 23. "Earth Energies" (1991, ISBN 0809465124, 0809465132, 144 p.)
** UK edition: "Earth Energies" (1991/11, ISBN 0705406954)
** French edition: "Les énergies telluriques" (1991, ISBN 2734405962)
** German edition: "Erdenergien" (1991, 1999, ISBN 906182219X, 3933468841)
** Danish edition: "Jordens energier" (1993, ISBN 8715085805)
** Spanish edition: "Energías de la Tierra" (1993, ISBN 8478382305)
* 24. "Cosmic Duality" (1991, ISBN 0809465167, 0809465175, 144 p.); The concept of duality (good/evil, black/white, male/female) is discussed in depth. Topics include Zoroastrianism, Satanism, conceptions of God and Goddess, demon possession and exorcism.
** UK edition: "Cosmic Duality" (1992/02, ISBN 0705406962)
** French edition: "Le dualisme dans l'univers" (1991, ISBN 2734406020)
** German edition: "Die kosmische Dualität" (1991, 1999, ISBN 9061822262)
** Danish edition: "Kosmiske modsætninger" (1993, ISBN 8715090086, 8715085805)
** Spanish edition: "Dualidad cósmica" (1993, ISBN 8478382356)
** Japanese edition: "二原理の書 (Nigenri no sho)" (2006/07, ISBN 4903077047, 134-page one-shot paperback)
* 25. "Mysterious Lands and Peoples" (1991, ISBN 0809465205, 0809465213, 144 p.)
** UK edition: "Mysterious Lands and Peoples" (1992/03, ISBN 0705406970)
** French edition: "Terres et peuples mythiques" (1991, ISBN 2734406101)
** German edition: "Rätsel vergangener Kulturen" (1992, 2005, ISBN 9061828406, unknown)
** Danish edition: "Mystiske lande og folk" (1993, ISBN 8715085805)
** Spanish edition: "Tierras y gentes misteríosas" (1993, ISBN 8478382364)
** Brazilian edition: "Terras e povos misteriosos" (1995, no ISBN/OCLC issued/known)
* 26. "The Mind and Beyond" (1991, ISBN 0809465256, 0809465264, 144 p.)
** UK edition: "The Mind and Beyond" (1992/10, ISBN 0705406989)
** French edition: "Au-delà de la pensée consciente" (1992, ISBN 2734406160)
** German edition: "Rätsel des Geistes" (1992 ISBN 9061828457)
** Danish edition: "Det grænseløse sind" (1993, ISBN 8715090264, 8715085805)
** Spanish edition: "La mente y el más allá" (1993, ISBN 8478382348)
** Brazilian edition: "Para além da mente" (1996, no ISBN/OCLC issued/known)
* 27. "Mystic Quests" (1991, ISBN 0809465299, 0809465302, 144 p.)
** UK edition: "Mystic Quests" (1992/10, ISBN 0705406997)
** French edition: "La quête mystique" (1992, ISBN 2734406217)
** German edition: "Auf den Spuren uralter Mythen" (1992, 2005 ISBN 9053905529, OCLC 180891270)
** Danish edition: "Guddommelige spor" (1993, ISBN 8715085805)
** Spanish edition: "Búsquedas míticas" (1993, ISBN 8478382275)
* 28. "Search for Immortality" (1991, ISBN 0809465345, 0809465337, 144 p.)
** UK edition: "Search for Immortality" (1992/10, ISBN 0705405842)
** French edition: "La recherche de l'immortalité" (1992, ISBN 2734406268)
** German edition: "Wege zur Unsterblichkeit" (1992 ISBN 9061829097)
** Danish edition: "Drømmen om udødelighed" (1993, ISBN 8715090272, final Danish-language series release)
** Spanish edition: "Prolongamento da vida" (1993, ISBN tbd)
** Brazilian edition: "Prolongamento da Vida" (1996, no ISBN/OCLC issued/known)
* 29. "The Mystical Year" (1992, ISBN 080946537X, 0809465388, 144 p.)
** UK edition: "The Mystical Year" (1992/03, ISBN 0705405850)
** French edition: "Rites et traditions de par le monde (1992, ISBN 2734406314)
** German edition: "Das mystische Jahr" (1992, 1999, ISBN 9061829100, 3933468914)
** Spanish edition: "El año místico" (1993, ISBN tbd)
* 30. "The Psychics" (1991, ISBN 0809465418, 0809465426, 144 p.)
** UK edition: "The Psychics" (1992/12, ISBN 0705409953)
** French edition: "La recherche de l'immortalité" (1992, ISBN 2734406268)
** German edition: "Die Parapsychologie" (1992 ISBN 9053905553)
** Spanish edition: "Los médiums" (1993, ISBN 8478382410)
** Brazilian edition: "Os paranormais" (1996, no ISBN/OCLC issued/known)
* 31. "Alien Encounters" (1992, ISBN 0809465450, 0809465469, 144 p.); Discusses extraterrestrial encounters and possible abductions.
** UK edition: "Alien Encounters" (1993/03, 2003/04 ISBN 0705409961, 1844470008)
** French edition: "Du surnaturel à l'extraterrestre" (1993, ISBN 2734406411)
** German edition: "Unheimliche Begegnungen mit Ausserirdischen" (1993, 1999, ISBN 9053905561, 3933468949)
** Spanish edition: "Encuentros con extraterrestres" (1993, ISBN 8478382178)
** Brazilian edition: "Contactos alienígenas" (1996, no ISBN/OCLC issued/known, final Portuguese-language series release)
** Chinese edition: "遭遇外星人 (Zao yu wai xing ren)" (2002/02, ISBN 7540728167, 184-page paperback)
* 32. "The Mysterious World" (1992, ISBN 0809465493, 0809465507, 144 p.)
** UK edition: "The Mysterious World" (1993, ISBN tbd)
** French edition: "Le monde invisible" (1993, ISBN 2734406454)
** German edition: "Unbekannte Welten" (1993 ISBN 905390557X)
** Spanish edition: "El mundo misterioso" (1993, ISBN 8478382429)
** Chinese edition: "神祕的世界 (Shen mi de shi jie)" (1996, ISBN 0783555547, US publication for Chinese-speaking citizenry)
* 33. "Master Index and Illustrated Symbols" (1992, ISBN 0809465086, 0809465094, 144 p.)
** Spanish edition: "Índice general" (1993, ISBN tbd)

### Slipcase

While the series was being released for the first time, the publisher had enabled its subscribers to separately order a silver imprinted hardboard slipcase, executed in black faux leather in emulation of how the books themselves were executed and able to hold three volumes. Already relatively rare to begin with when it was issued originally, this slipcase is hard to come by on current used-book markets.

### Excerpt editions

The publisher released a 96-page softcover excerpt edition in 1989. Titled "A collection from Mysteries of the Unknown" (OCLC 21492777, no ISBN issued), the in Prussian blue wrapped magazine-style book was just that, a sampling for prospective subscribers who were inquisitive about what the main series was all about, with its contents partially lifted from volumes 2 and 6.
A much more substantial 436-page excerpt paperback edition was released in 1997 by the Quality Paperback Book Club (New York) publisher, under a full license from Time-Life Books, Inc. Titled "Mysteries of the Unknown" (ISBN 0783549121), after its series namesake, it had its chapters roughly organized along the lines of the series volumes. In 2006, the excerpt book was reissued (ISBN 0760781095) by Barnes & Noble on behalf of their bookstore chain, again fully licensed by then-owner of Time-Life Books, Direct Holdings Americas Inc.

### Home market reprints

Home market DTC sales started to slow down from 1991 onward and it was the subsequent year decided to stop adding new titles to the series in order to free up the editorial staff for new series projects. This did not mean that the Mysteries of the Unknown series was discontinued however, as an additional distribution channel had in the meantime become employed as well, the regular retail bookstore channel. The added revenue that channel generated caused series volumes to remain reprinted over and over again, well into the late-1990s. The series' lifespan was additionally lengthened by the publication licenses extended to third-party home market publishers, like Barnes & Noble Books, the eponymous publishing arm of the aforementioned bookstore chain.

### Spinoffs

In 1989-90 while the series publication was still ongoing, a locally developed German-language Geheimnisse des Unbekannten Mystische Reise zur 6. Dimension board game was released twice in Germany by Time-Life Books B.V. as the only known such companion release, and a further indication of the series' popularity in Germanophone Europe.
Pursuant the main series, Time-Life Books published the near-concurrent 24-volume companion series, Collector's Library of the Unknown, from 1991 through 1993 as well. These concerned deluxe facsimile faux-leather bound reproductions of eyewitness accounts written by people who had firsthand experience with any of the events covered in the main series or by experts on any of these matters. Though smaller, the volumes were on purpose executed in a style similar to the main series in order to reinforce the kinship between the two series. Additionally, a subsequent ten-tape Time Life Video World of the Supernatural documentary series release on the VHS home video format had followed suit in 1995 (OCLC 35275139), which was like the progenitor book series supported by a television ad campaign. One year later subsidiary Time-Life Audiobooks reissued (part of) the series as taped audio cassette books in both English as well as Chinese (OCLC 818865412), with newly assigned ISBNs for each.
Despite the fact that Time-Life Books had largely withdrawn from book publication in 2003, the subsequent iteration of the publisher did release two additional Mysteries of the Unknown single-book titles on an ad-hoc basis, being largely a rehashing of the considerable editorial effort that was undertaken for the main series thirty years earlier. The titles thus released were,
* "Mysteries of the Unknown, Inside the World of the Strange and Unexplained" (2014/09, ISBN 9781618933522, 272-page paperback); presented as a Time-Life Books: Be An Instant Expert outing, the book was originally solicited as "Mysteries of the Unknown, An Encyclopedia of Unexplained Phenomena" – essentially a truncated version of the 1997 excerpt edition.
* "Mysteries of the Unknown: Inside the World of the Strange and Unexplained" (2019/10, ISBN 9781547850501, 96-page single LIFE Explores magazine-style theme issue); essentially an even further truncated variant edition of the already truncated 2014 release.

## Promotion

For almost a decade, Time-Life Books supported their Mysteries of the Unknown book series with a TV ad campaign that consisted of commercials that would air during prime time through broadcast and cable television networks such as TNN, Nick at Nite, MTV, VH-1, and TNT. In the process the series became one of the publisher's most, if not the most, advertised on television. Conceived by the New York City-based Wunderman Worldwide agency and Time-Life's own Tom Corry, the ad campaign stood out for its vigor and longevity as it touted a plethora of variant commercials, many of which currently featured on YouTube. The overall marketing campaign, which included the commercial concepts, even won series project manager Corry a Diamond Echo marketing award. A non-exhaustive selection of this series of commercials includes among others,
* The first commercial advertising Mysteries of the Unknown aired in September 1987; the voice-over narration started with "Chicago: a man is about to board a routine flight, and suddenly he pauses and walks away. An hour later, the plane goes down in flames. It's dismissed as chance." One- and two-minute versions of this commercial were aired.
* A second commercial aired in September 1988; the voice-over narration by renowned voice performer Don LaFontaine stated: "How would you explain it? A woman in Wisconsin is doing the dishes when suddenly she's possessed by a terrifying feeling. She's positive that her young daughter has just been in an accident. She quickly makes a desperate phone call only to learn that her feeling was true. How would you explain this? A dozen people around the world who never met each other describe an encounter with a being from space and their descriptions of the creature match almost exactly [sketch art of grey aliens appear on the screen during this narration]. And how do you explain this? A man's heart stops beating in a hospital and he sees a blinding light that doesn't frighten him but fills him with an indescribable feeling of peace. And how can you explain the growing number of people who feel that they've had a brush with something beyond our everyday understanding. Maybe no one can fully explain these things but they can no longer be ignored. That's why Time Life takes a serious look into this world with a remarkable new series, Mysteries of the Unknown, to provide an objective and comprehensive look at what may lie beyond our ordinary reality. How can you explain this? Four men are drawn to an ancient Anglo-Saxon fort site of a fierce battle. They enter the shadows of a ring of trees and without warning one of them is grabbed by an unseen force lifted five feet in the air and suspended for 30 full seconds. There are so many hints of a world more remarkable than we ever imagined and of abilities that we barely suspect." Images of Stonehenge and a picture of bloody hands on a window are shown.
* In 1989, actress Julianne Moore appeared in a Mysteries of the Unknown commercial explaining out-of-body experiences. The narration describes her waking up in the middle of the night with the feeling of something cold on her shoulder, only to find that she was affixed to the ceiling, looking down at her body from above.
* On New Year's Day of 1990, Time-Life had the one-minute "Discover A World That Can No Longer Be Ignored" commercial for Mysteries of the Unknown aired in conjunction with TV Guide. In it, it was explained how people could earn a bonus gift in the form of ten "power crystals (...) for enhancing concentration" by drawing in a full moon over a Stonehenge depiction on the in TV Guide enclosed reply card, they had to send in.
* The last known televised series commercial concerned the one broadcast on Sci-Fi Channel in 1997 which was presented by Marina Sirtis, who had in the meantime come to fame for her role on Star Trek: The Next Generation. This commercial stands out as being the only one presenting the series with its volumes in dust jackets (indicative of them being bookstore retail copies) which incidentally, were not the ones for the Barnes & Noble edition that were concurrently released that year.
And while new titles additions to the series was halted in 1992, sales and associated activities, of which the latter-day Sirtis commercial was but one, continued unabated right up to the point where Time-Life Books, Inc. ended its very existence in December 2003 after having already become defunct two years earlier.
The television ad campaigns were complementary to Time-Life's standard operating procedure of sending out elaborate multi-sheet direct mailings to their already existing customer database (which incidentally, had been professionalized by Corry in the early 1980s as one of his first assignments at Time-Life prior to his involvement with The Enchanted World and Mysteries of the Unknown), in which a series was introduced in detail to a potential subscriber; having taken out a subscription once, a customer was then registered in Time-Life Books' customer database, at the time a crucial business model marketing tool for the company, making that customer eligible for receiving the company's book series promotional direct mailings henceforth.
As was customary for Time-Life Books at the time when a subscription was taken out, the first book sent (typically the "Mystic Places" volume in this case, though other volumes were later offered up for assessment as well) was done so on a ten-day trial basis at a reduced price, after which each bi-monthly next installment could be assessed by customers on the same basis. In addition, US customers who responded by telephone to the television ads were in 1990 rewarded with a free gift consisting of the "Psychic Powers" video tape, which was not included in the above-mentioned ten-tape series released five years later, and therefore remained an actual exclusive. Until 1990 that first book sent came additionally with a free bonus gift in the form of a deck of ESP determination cards. After 1989 that deck of cards was as free bonus gift replaced by a quartz crystal in a felt jewelry pouch. Customers were allowed to keep either bonus gift even if they decided to return the volume it came with.