The Mare ' s Nest The Mare ' s Nest is a 1964 book by David Irving , focusing on the German V - weapons campaign of 1944 – 45 and the Allied military and intelligence effort ( Operation Crossbow ) to counter it . The book covers both sides of the story – the Allied arguments over how to interpret intelligence concerning the V - weapons ( or even whether they existed ) and the German debate over how to deploy the new weapons to make the most of their supposed capacity to reverse the tide of the war . During his research for the book , Irving discovered that the Allies had broken the German Enigma code , over a decade before that became public knowledge , but agreed to keep it secret . " The Mare ' s Nest " was well received by reviewers and those involved in Operation Crossbow and has been widely cited by authors writing about the V - weapons programme , even after the eclipse of Irving ' s reputation as a result of his Holocaust denial . Publication history . The book was Irving ' s second , published the year after his best - seller " The Destruction of Dresden " , and had its origins in the success of that book . Irving had intended to return to studying for a degree but abandoned his plans when his publisher proposed that he should write two more books , covering the V - weapons programme and the life of Adolf Hitler . He discovered that Winston Churchill ' s scientific adviser , Lord Cherwell , had been closely involved in tracking the V - weapons and that Cherwell ' s papers were held at Nuffield College , Oxford . Irving was given full access to the archive and made a startling discovery : that the Allies had been reading the German codes , a fact that was still regarded as top secret . He began to fear that he would be denied access to the archive if the authorities realised that he had uncovered ULTRA , the Allies ' wartime programme of decripting the Enigma machine codes and other German codes and cyphers . As he later put it , he resorted to doing " the unthinkable . I began borrowing documents , taking them down to London to copy . But I always sedulously returned them . " Irving nonetheless worked the secret material into his book , writing an entire chapter about Enigma in the first draft of " The Mare ' s Nest " . When it came to the attention of the authorities , " one night I was visited at my flat by men in belted raincoats who came and physically seized the chapter . I was summoned to the Cabinet Office , twelve men sitting around a polished table , where it was explained to me why [ the information ] was not being released and we appeal to you as an English gentleman not to release [ it ] . " Irving cooperated and withdrew the chapter , but by this time he had copied enough material from Cherwell ' s archive to furnish several more books . ULTRA remained secret for another decade . The book ' s title comes from a phrase used by Lord Cherwell to describe the V - weapons ; he was sceptical of the existence of the V - 2 rocket , regarding it ( wrongly , as it turned out ) as technologically infeasible , and referred to it as a " mare ' s nest " ( meaning a remarkable discovery which later turns out to be illusory ) . Reception . The book was well received at the time by reviewers . Writing in " The Economist " , William Kimber called it " remarkable " for its coverage of both sides , Allied and German . He concluded that the book shows that the British reached the right conclusions , despite errors along the way , while the Germans hindered their own efforts with disputes between the army , air force , SS and civilian ministers . " The Times " noted that the book highlighted how the hunt for the V - weapons was punctuated by " conflicts of personality between scientists , intelligence officers , and Service leaders " , while at the same time conveying " the efficiency of the British Intelligence Services at the lower level " even if the higher - level co - ordination was sometimes lacking . " The Guardian ' s " Clare Hollingworth noted that the book " provides some excellent quotations from intelligence documents , both British and German , as well as sketches of Peenemünde and of the [ V - 2 rocket ] " and suggested that " perhaps scientists or soldiers engaged in rocketry " would find it useful . William Connor , under his pen - name " Cassandra " , called it in the " The Daily Mirror " " one of the most fascinating books I have read for a long time " . Duncan Sandys , who had chaired the Crossbow Committee responsible for co - ordinating the Allied response to the V - weapons , called it an " authoritative account of the V - weapon offensive " in his review for the London " Evening Standard " . He commended the author for having " successfully woven [ his research ] together into a coherent narrative , written in a brisk style " , though he faulted Irving for having relied too heavily on Lord Cherwell ' s papers , with the result that he had treated " the problem as primarily one of scientific intelligence and [ paid ] insufficient attention to other more important aspects of the operation . " Nonetheless , Sandys concluded , " students will find in The Mare ' s Nest a mine of important information , while much wider circles will enjoy David Irving ' s vivid presentation of a strange story . " The book has been widely cited by authors covering the V - weapons programme . Even after Irving ' s reputation was destroyed after his exposure as a Holocaust denier , Michael J . Neufeld of the Smithsonian ' s National Air and Space Museum has described " The Mare ' s Nest " as " the most complete account on both Allied and German sides of the V - weapons campaign in the last two years of the war . "