Heroes and Demons ( episode ) When several crew members disappear inside Harry Kim ' s " Beowulf " holodeck program , the holographic Doctor is the only one who can rescue them . Summary . Teaser . Lieutenant B ' Elanna Torres encounters an irregularity in the transport of samples from a nearby protostar ; one of the containers is filled but the other is empty . After this irregularity is corrected on a second attempt , Torres informs Captain Janeway that she will perform a full , six - hour spectral analysis on both containers . It is concluded that the samples could be harnessed to improve the power converters by fifteen to twenty percent . Janeway attempts to locate Ensign Harry Kim to expedite the analysis , however the computer informs her that Kim is not aboard the ship . Janeway then goes to the bridge , where Lieutenant Tuvok and Commander Chakotay aid her in a more thorough search of the ship for Kim . Noticing that Kim was last seen on the holodeck , Tuvok performs an intensive scan of the holodeck , though there is a high amount of interference . Realizing that the holodeck program cannot be shut down , Tuvok and Chakotay enter the program while it is still in progress . Act One . They discover the holonovel , " " , which is an emulation of " an ancient English epic set in 6th century Denmark " as described by Chakotay . Soon after this discovery , they encounter a holodeck character who shoots a projectile at Chakotay , though missing him . Tuvok and Chakotay come to the conclusion that holodeck commands and safeguards may be inoperative . The holodeck character identifies herself as " Freya , daughter of King Hrothgar " , who believes they are possibly malevolent intruders . Asking if they are Beowulf ' s men , Chakotay finds an opportunity to befriend Freya , by declaring that they are indeed such . Chakotay realized that since Kim chose the holodeck program , he was probably playing the lead character : Beowulf . Tuvok and Chakotay decide to remain with Freya , in hopes that she may aid them in their search for Kim . Freya alarmingly mentions that Beowulf has died . Freya takes them to the castle of King Hrothgar , to " avenge the death " of Beowulf . The men in the king ' s company tell Tuvok and Chakotay that Beowulf died with thirty warriors , at the hands of a merciless monster named Grendel . Tuvok asks for Beowulf ' s body , but Freya informs him that Grendel dragged the body to its lair , although nobody saw the battle . The king loses hope because of Beowulf ' s incapability in killing Grendel , and is terrified . The king and his company are doubtful of Tuvok and Chakotay ' s worthiness , and as a test require them to hold sentry of the castle . Tuvok and Chakotay inform Janeway of the program . Tuvok suggests that Kim may truly be dead . Janeway requests tricorder analysis of the program . Tuvok and Chakotay discuss " Beowulf " as an example of Human mythology . Tuvok sees it as illogical , claiming that Vulcan s do not write about demon s . Chakotay discusses alien mythology that relates to " Beowulf " , such as Vok ' sha of Rakella Prime . It is discovered that the protostar emitted energy that caused the holodeck to malfunction . This caused Kim to be converted into energy . One meter in diameter , a bright mass appears in the program . Janeway calls for a report , but no answer . Torres tries to transport them out of the program but it does not work . Soon , she loses their life signs . Act Two . The crew determines that photonic energy created a defect that de - materialized Kim , Chakotay , and Tuvok . Lieutenant Tom Paris is convinced that they may still be recoverable . To prevent a rescue team being consumed in the same fashion , Paris suggests that The Doctor could be used , " " because a hologram cannot be converted into energy because it ' s already energy " " . The Doctor , who is normally confined to sickbay , will be able to transfer to the holodeck since it also has holo - emitters in place and would also have the advantage of being corporeal or incorporeal at will . The Doctor is asked to interact with the characters and discover the root of the malfunction . Kes talks with The Doctor while he learns background information concerning " Beowulf " . Kes asks if The Doctor is nervous about the task , since it is different from his intended programming . The Doctor admits that the unfamiliarity of the environment outside of sickbay makes him uneasy . Kes explains that it will be a chance for The Doctor to become independent and more Human . Kes suggests a name for The Doctor , and he agrees to further research a suitable name for himself . The Doctor encounters Freya in the same fashion as Chakotay and Tuvok , and already knows every important detail about her , due to his copious research of " Beowulf " . After Freya gloats of her exploits , The Doctor asks Freya for Grendel ' s location . Freya finds The Doctor ' s willingness to locate such an epic monster as courageous and admirable . The Doctor says his name is " Schweitzer " ; Freya says it is a warrior ' s name . She agrees to lead him to Grendel . Freya begins to forage sub - arctic fungi , for a broth in a warrior ' s pre - battle concoction . The Doctor comments on the fungi in a clinical tone , describing it as detrimental to physical activity . Freya counters that anything that does not kill , makes one strong . The King is introduced to The Doctor , and is received in a nearly identical fashion as Chakotay and Tuvok , with an identical script . The Doctor engages with one of the King ' s men , Unferth , in a sword fight to prove his worthiness in fighting Grendel . The Doctor slightly wounds the foe , and gives him medical advice thereafter . He gains the adulation of the King ' s audience as they chant " Schweitzer ! " Act Three . The men in the castle invite The Doctor to a feast of meat . The Doctor begins to gloat of unusually dry exploits ( most notably " Parinisti measles " ) with copious amounts of advanced medical terminology . This confounds the men . Freya sits with The Doctor near a roaring fire . Freya confesses her unease about Grendel , and asks The Doctor for counsel . Freya fears her courage would falter , but says The Doctor has bolstered it . Freya grows romantically attached to The Doctor , and they kiss . Freya invites The Doctor to her bed , but he declines , being interrupted to readings of photonic energy . It is Grendel . Its tentacle grasps onto The Doctor ' s arm , and as he is suddenly aware of " feeling " the creature ' s touch , he frantically requests to be transported to sickbay . He makes it ; however , when he arrives his arm is now missing . Act Four . The Doctor is soon given a new arm . It ' s apparent the photonic energy can disrupt his magnetic cohesion . The Doctor ' s tricorder readings cause Paris and Torres to research the energy further , discovering synaptic pattern s . Wondering if the protostar samples could exhibit the same behavior , they go to engineering to run tests . Adding a polarization field into the container , they indeed get a reaction . They read highly complex synaptic patterns , but then the sample breaks free of the container and moves throughout the ship . Paris and Torres monitor its movements and try to catch it in a containment field , but , surprisingly , it avoids the field . They suppose the synaptic patterns are a kind of neural net , an indication of a lifeform . Janeway interrupts , having detected the sample ' s movement from the bridge . When Paris and Torres inform the captain about their suspicion , she orders them to let the organism escape through the hull . Proactively , she sends damage control teams and orders force fields to get in place after it leaves . It does so without permanent damage . On the viewscreen , Janeway watches as the photonic life form moves forward and enters a large circle of light , then disappearing . Act Five . The crew determines the lifeform was rejoining a photonic lattice : a sort of " home " for the photonic organisms . In sickbay , Janeway thinks she understands and reiterates the evidence to Torres and The Doctor . She concludes that Kim , Tuvok , and Chakotay were converted into energy and made up the three patterns present in the photonic mass . It is believed that Grendel is holding the crewmen hostage for the seizure of the photonic samples , which are in fact its living brethren . The Doctor suggests releasing the sample to Grendel as a sign of goodwill to the organisms may lead to the release of the " Voyager " crewmen . Janeway agrees . Bringing the remaining organism in a container , The Doctor enters the holodeck . The Doctor claims the sample is a talisman to defeat Grendel . Unferth concludes that since no man has the power to destroy Grendel , The Doctor must be consorting with Grendel . Unferth attempts to slay The Doctor , but Freya blocks the attack with her body , eventually dying in the process . The warrior takes the sample and flees . Freya bids The Doctor farewell , concluding with a kiss . The Doctor takes her sword , and goes to the king to retrieve the sample . The Doctor proclaims himself the only man capable of defeating Grendel . Unferth accuses The Doctor of killing Freya , but he is quelled by The Doctor ' s bravado . The Doctor threatens Unferth with a lit torch , and proclaims " the only reason you won ' t die is because I ' ve taken an oath to do no harm . " The " oath to do no harm " is the Hippocratic Oath that is used among Starfleet medical personnel . The Doctor calls for Grendel , who appears in the throne room . The Doctor sets free the photonic organism in the sample container . He asks Grendel to return the crewmen . Grendel agrees and Chakotay , Tuvok and a baffled Kim are all restored to normal before leaving the ship . Janeway praises The Doctor for aiding in the establishment of a peaceful relationship with a new species . Moreover she tells The Doctor that she is giving him a special commendation for exemplary performance as a chief medical officer . The Doctor is humbled and thanks Janeway . The Doctor is asked if he wants to be addressed with a name , however he admits that Freya ' s death made " Schweitzer " painful and chooses to keep his current designation as " The Doctor " . Memorable quotes . " " This ancient Earth culture seems fascinated with monsters . " " " " Every culture has its demons . They embody the darkest emotions of its people . Giving them physical form in heroic literature is a way of exploring those feelings . The Vok ' sha of Rakella Prime believe that hate is a beast which lives inside the stomach . Their greatest mythical hero is a man who ate stones for twenty - three days to kill the beast , and became a saint . " " " " Such fables are necessary only in cultures which unduly emphasize emotional behavior . I would point out there are no demons in Vulcan literature . " " " " That might account for its popularity . " " " " Grandiloquence notwithstanding , that would qualify as a description of Mr . Kim . " " " " Are you a master of herb lore ? " " " " Well , in a way , I suppose I am . " " " " You are truly a man of many talents , Lord Schweitzer . Your people must value you greatly . " " " " You would think so . " " " " Fire is not the only heat , Lord Schweitzer . You know where I sleep . " " " " Sometimes I believe I can see the moment of my own death . It comes in battle , I think , my sword raised high . It is said that fate often spares a doomed warrior if his courage can prevail , but there have been days when I have felt my own courage falter , and then you came . " " " " The only reason you won ' t die is that I took an oath to do no harm . " " Links and references . References . annotation ; " Amanita muscaria " ; annular confinement beam ; antibody ; antler ; apple ; " atuta " ; away mission ; base pair sequencer ; bear ; beast ; " " ; Beowulf ; biobed ; bioelectrical pattern ; broth ; candle ; centaur ; chandelier ; Chief Medical Officer ; convulsion ; Dane ; delirium ; Denmark ; demon ; Earth ; elk ; endoplasmic virus ; epic poem ; first contact ; fungi ; Gar - Dane ; gesture ; Grendel ; ; Heatho - bard ; herb ; Hippocratic Oath ; holo - character ; holodeck ; holodeck conversion node ; hostage ; imaging control system ; inoculation ; internal systems scan ; king ; kinsman ; kiss ; lair ; lie ; log ; long sword ; matter conversion node ; mead ; molecular analysis ; neural net ; Parinisti measles ; peace treaty ; phase spectrum analysis ; photonic lattice ; photonic lifeform ; photonic matter ; poison ; power converter ; primary imaging matrix ; protostar ; Rakella Prime ; saint ; scan analysis ; schematic ; ; Scyld ; setting ; shieldmaiden ; short range scan ; Sire ; sorcerer ; spear ; stab wound ; Starfleet ; stomach ; sub - arctic climate ; sword ; synaptic pattern ; talisman ; torch ; transporter ; trespassing ; Viking ; Vok ' sha ; Vok ' sha saint ; Vulcan literature