The Immunity Syndrome ( episode ) After Spock senses the destruction of the Vulcan - manned starship " Intrepid " , the " Enterprise " encounters an enormous single - celled organism that feeds on energy which threatens the galaxy as it prepares to reproduce . Summary . Teaser . Headed for much - needed shore leave , the gets a call from Starbase 6 . Through massive subspace static , Lieutenant Uhura can only hear " " Intrepid " " and a sector coordinate . As she tries to reconnect , Spock suddenly appears stricken and informs Kirk and McCoy that the " Intrepid " – an all - Vulcan starship – has just " died " with all hands aboard . As Spock leaves for the sickbay with McCoy , Uhura gets through to Starbase 6 . The " Intrepid " was investigating the Gamma 7A system in sector 39J when communication with the system and the ship both ceased . The " Enterprise " is commanded to divert to the area . As they change course , Ensign Pavel Chekov conducts a full long - range scan and reports that the Gamma 7A system , with its billions of inhabitants , is dead . Kirk notes that the system has billions of inhabitants but Chekov states again that it is simply dead . Act One . Diverted to investigate , the " Enterprise " encounters a " zone of darkness , " an area of space so black not even star light penetrates through . Spock says its location lies directly in the " Intrepid " s , as well as the Gamma 7A system ' s , projected path . The zone also appears to have a strong attractive force about it . Passive means of gathering information , such as sensor s and probe s , are ineffective as no data comes back from the zone , just a very loud noise , like feedback from a sound system . The sound nearly knocks everyone on the bridge out , such as Kyle , Uhura , and Chekov . Dr . McCoy reports to Kirk that half the crew members on the " Enterprise " fainted , but he and Nurse Chapel are treating them with stimulant s . Kirk asks Spock for an analysis on the dark area ahead . Spock can provide none due to insufficient information , which irritates the captain . Spock comments that it is not liquid , gaseous , or solid , nor is it a nebula , and since the " Enterprise " s deflectors were activated by it , it must be some form of energy . Finally , Kirk decides to penetrate the zone . Once inside , the attractive force appears to grow stronger , pulling the " Enterprise " towards the center . In addition , energy is being drained from both the ship and the crew ; McCoy orders stimulants to keep everybody going . Later , McCoy reports to Kirk that according to the medical monitors in sickbay , people are dying – they are " all " dying . Act Two . Kirk enters engineering where Scotty informs him that the " Enterprise " s power levels are down by twelve percent and steadily decreasing . On the bridge , Spock notes that the ship is being pulled toward the center of the zone of darkness by an unknown force . Scott and Spock find that normal laws of physics seem to be reversed within the zone . Reverse thrust , for example , creates " forward " motion . Forward thrust is ordered by Kirk , which slows ( but does not stop ) the forward motion . Later , McCoy announces at a meeting in the briefing room that as the " Enterprise " moves further into the zone of darkness , the weaker the crew ' s life signs become and he cannot determine why that is . Kirk has Scotty channel all impulse and warp power into one giant thrust forward , so the " Enterprise " has a chance to escape the zone , and Scotty plans to reserve power for the shields in case they do not . Kirk dismisses his crew , but Spock remains behind to discuss with Kirk that the crew of the " Intrepid " may have done all of these things they are planning on doing to escape their current predicament and yet they all died . Kirk disagrees , noting that Spock himself has commented on how illogical the whole situation is , thus the " Intrepid " s crew may not have undertook the same course of action . Spock concedes to this point , but says the crew of the " Intrepid " did not know what was killing them , sensing earlier that he felt a " touch of death " from the crew . He also says the crew felt astonishment just prior to their deaths . Scott transfers the necessary power for the large scale thrust in the emergency manual monitor area of engineering . Kirk announces to the whole crew the plan via the intercom and to brace themselves . The attempt fails however , and the best they can do is to maintain thrust against the pull . The " Enterprise " then penetrates deeper into the zone , the mystery is finally revealed at its center – an 11 , 000 mile long , single - celled creature , which apparently radiates the zone as a protective covering . Spock announces that it is living . Act Three . A quick analysis reveals the creature to feed on energy , explaining the drain on machines and lifeform s and it can reproduce like any other organism would , but the crew don ' t presently know what . The entity must be destroyed in order to save the ship and crew , but more information is needed . A shuttlecraft is fitted with special instruments to take detailed readings from inside the creature itself . Both Spock and McCoy eagerly volunteer for the mission , despite the fact that it means almost certain death for the one selected . The confrontation between both men , each an expert in his own way , leaves Kirk with an agonizing choice . Finally , he decides : " " I ' m sorry Mr . Spock ; you ' re best qualified to go . " " Once inside , Spock sends back telemetry , but his power systems rapidly fade , and what power the shields have will nevertheless only last 47 minutes . His last transmission informs the crew that the 40 chromosomes of the creature are lining up in an apparent first step toward dividing – the creature is preparing to reproduce and soon it will destroy the entire universe if not stopped . Spock radios back how to destroy the creature , but his transmissions are increasingly garbled and unintelligible . Act Four . Fearing Spock to be dead , Kirk and McCoy reflect over what he was trying to say . Kirk makes the observation that when the creature divides , the " Enterprise " will be like an invading virus ; McCoy is fascinated by the idea of being antibodies of their own galaxy . The analogy gives Kirk an idea – use a charge of antimatter in the chromosome body to destroy the entity . The ship goes into the creature itself , and a probe with the antimatter charge is implanted at point - blank range to prevent currents in the protoplasm from carrying it away from its target . Power levels are quickly dropping , however , and the ship backs out of the creature . As it does so , however , sensors pick up the shuttlecraft with Spock still alive . Despite the power drain ( and Spock ' s protests ) , tractor beam s are activated . Power levels read dead as the charge explodes , just before the " Enterprise " exits the creature . Both the ship and shuttlecraft are thrown clear , with power levels restored . As Spock and McCoy argue over which tests were performed satisfactorily , the shuttlecraft is brought back aboard to the " Enterprise " s shuttlebay , and it resumes its course for the crew ' s well - earned shore leave . Memorable quotes . " " You find it easier to understand the death of one than the death of a million . You speak about the objective hardness of the Vulcan heart , yet how little room there seems to be in yours . " " " " " Insufficient data " is not sufficient , Mr . Spock . You ' re the science officer . You ' re supposed to have sufficient data all the time ! " " " " I ' m well aware of that , captain . " " " " " Suffer the death of thy neighbor , " eh , Spock ? You wouldn ' t wish that on us , would you ? " " " " It might have rendered your history a bit less bloody . " " " " Are you trying to be funny , Mister Spock ? " " " " It would never occur to me , Captain . " " " " Vulcan dignity ? How can I grant you what I don ' t understand ? " " " " Then employ one of your own superstitions . Wish me luck . " " " " Good luck , Spock . " " " " According to Spock ' s telemetry information , there are over forty chromosomes in the nucleus that are ready to come together , ready to reproduce . " " " If the energy of that organism only doubles , we ' re dead , and everything within a light year will be defenseless . " " " Well , all I know is , that soon there ' ll be two , four , eight , and more . The entire anti - life matter that that thing puts out could someday encompass the entire galaxy . " " " " Here we are . Antibodies of our own galaxy , attacking an invading germ . It would be ironic indeed if that were our sole destiny , wouldn ' t it ? " " " " Shut up , Spock ! We ' re rescuing you ! " " " " Why , thank you . . . Captain McCoy . " " " " The power levels are dead , sir . " " " " You may have just written our epitaph , Mister Scott . " " " " Spock , you ' re alive ! " " " " Obviously , captain . And I have some fascinating data on the organism . " " " " Don ' t be so smart , Spock ! You botched the acetylcholine test ! " " Background information . Remastered information . The remastered version of " The Immunity Syndrome " aired in many North American markets during the weekend of . Some of the effects shots were virtual recreations of the original footage ( corrected to factor in the absence of light ) , while others were more dynamic and showed angles of the " Enterprise " never before seen . The space amoeba retained its original shape and colorful design , but featured a more realistic and three - dimensional nucleus . Shuttlecraft shots were new , with interior windows rotoscoped to feature brand new shots of the amoeba . For much of the episode , the CG - " Enterprise " was depicted with impulse drive illuminated red , portraying the ship ' s struggle to remain in place . However , it must be pointed out that there is also a remastered mistake when Uhura asks Mr Spock - ' Exactly what are we looking for Mr Spock ? ' , to which Spock replies with a console tap - ' I would assume , " that " . ' In the original episode the dark nebulous mass on the view screen doesn ' t appear until Spock draws attention to it . But in the remastered version , the dark mass appears before Spock ' s statement . Links and references . References . acetylcholine test ; amoeba ; antibody ; anti - life matter ; antimatter ; asexual reproduction ; balloon ; biology ; " Bones " ; boundary layer ; breathing ; cell membrane ; chromosome ; Class F shuttlecraft ; Coalsack Nebula ; conqueror ; command pilot ; commendation ; damage control party ; death ; debris ; deflector shield s ; dizziness ; DNA code analyzer ; dust cloud ; eating ; energy ; enzyme recorder ; epitaph ; fainting ; fuse ; " " ; Gamma 7A system ; gas ; germ ; gravimetric force ; hangar deck ; impulse power ; intercom ; " Intrepid " , USS ; Intrepid casualties ; kilometer ; laboratory ; library computer ; life function indicator ; life indicator ; life monitor ; life support system ; light year ; liquid ; logic ; magnetic bottle ; magnetic storm ; magnitude ; martyr ; martyr complex ; mile ; Milky Way Galaxy ; nebula ; nucleus ; paralysis ; phaser bank ; protective shield ; protoplasm ; red alert ; reproduce ; Rest and Relaxation ; scanner ; science officer ; science specialist ; Sector 39J ; solid ; space amoeba ; star ; Starbase 6 ; sun ; Starbase 6 planet ; Starfleet ; stimulant ; superstition ; telemetry probe ; telepathy ; timing detonator ; tractor beam ; virus ; Vulcan ( planet ) ; Vulcan s ; wind tunnel ; zone of darkness