The Doomsday Machine ( episode ) The " Enterprise " discovers a weapon capable of destroying entire planets , and a commodore whose crew was killed by the machine jeopardizes the crew on a crazed mission of revenge . Summary . Teaser . On the , Lieutenant receives a faint and garbled distress signal . It is apparently a starship ' s disaster beacon , but Palmer is unable to make out any words aside from " Constellation " . At the same time , the " Enterprise " also encounters heavy subspace interference , which prevents the crew from reporting their discoveries to Starfleet Command . The " Enterprise " enters system L - 370 and finds that all seven planets in the system have been destroyed , smashed to rubble . Proceeding to system L - 374 , they find the same thing : debris where there were once healthy planets the previous year . All of the systems in the sector have been destroyed except for the two inner planets in L - 374 . In L - 374 , the " Enterprise " also finds her sister ship , the , commanded by Commodore Matt Decker , now a powerless wreck , drifting and apparently abandoned . As there is no apparent natural cause for the planetary destruction and the condition of the " Constellation " , Captain Kirk assumes that they were attacked and orders the " Enterprise " to go to red alert . Act One . Sensor scans show the " Constellation " to be running with minimal life support , using its reserve energy banks . All of its power plants are dead , and the bridge is uninhabitable . Subspace interference is preventing further sensor readings , as well as any communications beyond the distress signal . There are no other ships detected in the area , however , and Kirk orders the ship ' s status dropped to yellow alert . Kirk then orders Dr . McCoy , Montgomery Scott , and a damage control party to the transporter room . He intends to board the " Constellation " , and leaves Spock in command of the " Enterprise " . The landing party beams aboard a corridor on the " Constellation " and begins investigating . Scott and his team examine the engine room and find the warp engines totally destroyed , the impulse engines heavily damaged , and the phaser banks completely exhausted . The " Constellation " has clearly fought a pitched battle and lost . Kirk and McCoy , examining the rest of the ship , find no signs of the crew and no bodies . Wondering if the crew might have beamed down to one of the remaining planets , Spock ( on the " Enterprise " ) informs Kirk that the planets could not possibly sustain Human life : the inner planet having a surface temperature close to the melting point of lead and the second ' s atmosphere is simply too toxic to support Human life . When Scott , after giving his report on the condition of the engines to Kirk , suggests that they might play back the tapes of the captain ' s log , they proceed to the auxiliary control room . There , Kirk finds Commodore Decker , the sole survivor aboard , in a fugue state . McCoy gives him an injection with his hypospray and he starts to come around , eventually recognizing Kirk . As he begins to recover , Scott plays back Decker ' s log : Decker , still in shock and barely lucid , begins to remember what happened as he hears his log played back . Kirk orders the " Constellation " sensor tapes beamed back to the " Enterprise " for analysis by Spock . Decker describes how his ship was attacked and disabled and , unable to contact Starfleet due to heavy subspace interference , he beamed his crew down to the third planet . As the captain , he was the last man aboard when the ship was attacked again . The transporters were disabled , and he was stranded . Prompted by Kirk for a description of the attacker , Decker becomes increasingly distraught as he describes something " right out of hell " that destroyed the third planet , along with all four hundred of the " Constellation " s crew . Telling of how his crew begged for rescue as he sat helpless on the ship , he collapses in grief . Washburn reports that the ship ' s antimatter stores have somehow been deactivated , and Kirk asks Scott if a " general energy dampening field " could be responsible for that , as well as the subspace interference . Scott agrees that it ' s possible , but doesn ' t know of anything that could generate such a field . Decker , recovering somewhat , begins describing the planet killer in more detail . " " Miles long , with a maw that could swallow a dozen starships " , " Decker explains that the planet killer uses a pure antiproton beam to carve planets up into rubble . He couldn ' t tell if it was a ship or a living organism . Spock reports in from the " Enterprise " . From the sensor tapes , he has determined that the planet killer is an automated weapon designed to smash planets and digest the debris for fuel . As long as there are planets to consume , the device is self - sustaining . Spock and Sulu have used the locations of the ravaged star systems they encountered to calculate that the planet killer came from outside the galaxy , and that its projected path will take it through the most densely populated section of our galaxy . Speaking with McCoy , Kirk postulates that the planet killer is a " doomsday weapon , " a bluff created by an unknown maker and intended as a deterrent only . This one is roaming the galaxies , consuming everything in its path for fuel , including whole planets . Its alien makers are presumably long since dead . This becomes the operational theory , though the " Enterprise " never finds any evidence that confirms or denies it . McCoy is still concerned about Decker ' s mental condition , and wants to get him to the " Enterprise " sickbay . Decker , slipping back and forth between his authoritarian captain ' s persona and that of a grief - stricken trauma victim , at first refuses to leave his ship , but is convinced when Kirk offers to take the " Constellation " in tow . Decker ruefully notes to Kirk that he has never lost a command before . McCoy and Decker beam back to the " Enterprise " while Kirk and Scott remain on board the " Constellation " to rig her for towing . However , when McCoy and Decker materialize in the " Enterprise " transporter room , the red alert klaxons are sounding , and they both rush to the bridge . The planet killer has returned , and they find Spock in the command chair , reporting to Kirk on the " Constellation " as the planet killer turns to pursue the " Enterprise . " Act Two . Facing them with its gaping maw , the planet killer turns to pursue the " Enterprise " as Spock analyzes his sensor readings and concludes that they have little chance of deactivating the device without drawing an attack upon themselves . Kirk orders the landing party beamed back to the " Enterprise " , but the planet killer attacks the " Enterprise " before Kyle in the transporter room can do so . The transporters are damaged , as are communications , causing the " Enterprise " to lose contact with Kirk , now stranded aboard the " Constellation " with no viewscreen and no maneuvering ability . Kirk orders Scott to try to repair the impulse drive , while he and Washburn work on restoring the viewscreen . After the initial attack by the planet killer , the " Enterprise " evades and outruns it . Dr . McCoy reports no casualties , and Decker , already assuming an attitude of command , orders a status report from Kirk ' s chair . Warp and impulse engines are undamaged , but transporters and communications are under repair . Now some distance away , the planet killer stops pursuing the " Enterprise " , veers off , and resumes its course for the densely - inhabited Rigel system . Spock states his intention to keep his distance from the planet killer , circle around to pick up the landing party , and then evade the device ' s subspace interference so that they can warn Starfleet Command of the danger . Decker objects , stating that their primary duty is to protect Federation citizens , and that they must attack the planet killer immediately . He orders a 180 degree turn . Spock dispassionately ignores Decker ' s arguments and instructs Sulu to carry out his order . Decker , at this point , asserts his rank as a Starfleet commodore and assumes command of the " Enterprise " ( under General Order 104 , Section B , Paragraph 1a ) , despite the precise and logic al objections of Spock , as well as the more hysterical ones of Dr . McCoy . Spock points out that Decker ' s previous attempt to attack the planet killer resulted in the loss of his ship and the death of his crew . Momentarily losing his attitude of command authority , Decker admits his previous mistake and asserts that this time he will get much closer to the planet killer and attack it with full phasers . Spock protests that the device ' s hull is made of solid neutronium , and is therefore impervious to attack from a single ship . Decker ends the argument by ordering Spock to surrender command or be relieved of duty . Confronted with an official order from a superior officer , Spock has no choice but to let Decker assume command . McCoy , looking for a loophole in the regulations , offers to declare Decker medically unfit ( under what Spock describes as Section C of General Order 104 ) , but having had no time to perform a complete examination , his declaration would carry little to no weight . Decker ' s mask of authority again slips momentarily when he thinks McCoy might have a case for relieving him , but Spock ' s adherence to the spirit of the regulations makes his argument for him . Decker orders McCoy off the bridge and gives orders to set course for the planet killer and prepare for battle . The bridge crew looks on worriedly , but Sulu has no choice but to carry out his orders . As the " Enterprise " reverses course and approaches the planet killer again , Commodore Decker sits comfortably in the captain ' s chair , in full command mode . However , he still looks a wreck : unshaven , bedraggled , and wild - eyed . Spock , instead of returning to his science station , stands at attention by the captain ' s chair . Aboard the " Constellation " , Kirk and Scott are proceeding with repairs , oblivious to what ' s going on outside . Scott will have to use the warp control circuits to control the impulse engines , which will make the ship difficult for one man to handle . The " Enterprise " closes in on the planet killer , pushing its deflector shield s to the limit . The planet killer fires , weakening the shields further . Spock recommends retreating , but Decker , asserting his command status , takes the ship still closer . On the " Constellation " , Kirk and Washburn have repaired the viewscreen , and the first image that appears is the " Enterprise " , approaching dangerously close to the planet killer . The " Enterprise " fires its phasers and scores direct hits on the planet killer , to no apparent effect . Spock urgently recommends withdrawal , but Decker " notes " his recommendation and ignores it , ordering Sulu to lay down more phaser fire . Kirk desperately tries to contact the " Enterprise " , and when he cannot , orders Scott to get the impulse drive up and running as quickly as possible . The planet killer fires on the " Enterprise " again , disabling its shields and its power energizers . Lieutenant Palmer , the communications officer , also reports severe casualties on decks 3 and 4 and reports of an inner hull breach . The planet killer stops firing and begins pulling the " Enterprise " inside itself using a tractor beam , presumably to " digest " it as fuel . Spock says that they must veer off , and when Decker tries to continue the attack , he informs him that with warp power out , they must break away from the tractor beam within sixty seconds , or they never will . Decker , his irrational obsession now blatantly apparent to the crew , insists on trying to destroy the planet killer , but Spock warns him that if he does not order a withdrawal , he will relieve Decker of command using evidence of attempted suicide as proof of Decker ' s instability . Decker gives in , looking far less confident than he was just a few minutes prior , and orders Sulu to veer off , but it is too late ; the planet killer has the " Enterprise " in its tractor beam , and continues pulling her inside . Act Three . On the " Constellation " , Scott has managed to partially repair the impulse engine s , providing basic maneuverability . Running from console to console , Kirk starts the ship limping towards the " Enterprise " and the planet killer . On the " Enterprise " , Decker orders full power astern , but they still cannot break free from the tractor beam . Captain Kirk ' s plan is to attract the planet killer ' s attention by moving towards it , while the " Enterprise " remains stationary . He wishes aloud for phasers , and Scott tells him that he has one bank recharged . Kirk , delighted with his engineer , fires at the planet killer , causing it to immediately release the " Enterprise " from its tractor beam and come about to pursue the " Constellation " . With the planet killer rapidly approaching the " Constellation " , however , Kirk ' s plan suddenly does not seem like such a great idea . He orders Scott to retreat , and Decker , now excited at the prospect of having two ships to attack the monster , fires phasers again and orders the " Enterprise " to clear the area . The planet killer does not pursue them , and Spock opines that the device has a set defensive sphere ; it attacks any energy source encroaching the sphere . The " Enterprise " s warp drive and deflector shields will be out for one solar day , while repairs are proceeding on the transporter s and communications . The planet killer starts moving towards the " Enterprise " again , and Decker orders Sulu to maintain their speed and distance . The planet killer pauses to ingest rubble from the destroyed planets , and Spock notes that by refueling itself this way , the device can maintain its pursuit indefinitely , while the " Enterprise " , at its current speed , will exhaust its fuel in seven hours . Decker takes this to mean that they should attack now , but Spock once again points out the illogic of Decker ' s actions . He repeats his initial plan , insisting that they must pick up Kirk and the landing party and then get clear of the subspace interference so they can warn Starfleet about the planet killer . Before Decker can object , Palmer reports that ship - to - ship communications have been restored . Kirk hails the " Enterprise " through his communicator and Decker , back in command mode , insists on speaking for the ship . Kirk , expecting Spock , is surprised to hear Decker ' s voice . When he finds out that Decker has assumed command because Spock refused to attack the planet killer , Kirk , angry and insubordinate , calls Decker a " lunatic " and demands that he get the " Enterprise " out of the area . Decker , his mask again slipping a bit , allows Spock to give Kirk a status report . Kirk orders Sulu to take evasive action , and when Decker again tries to assert his command authority , Kirk orders Spock to relieve him , on his " personal authority as captain of the " Enterprise " . " Spock tells Decker that he is relieved , and even though Decker does not recognize his authority to do so , he sees that Spock will have him arrest ed if necessary , and that the crew will support the First Officer against him without question . In a final act of defiance , Decker claims to Spock , " " You ' re bluffing . " " only for Spock to simply respond , " " Vulcans never bluff . " " Seeing his authority is lost against an officer with so strong a will and crew support , Decker surrenders command . Spock takes the captain ' s chair and resumes command , to the evident relief of Sulu . Spock then orders Montgomery , a security officer , to escort Decker to sickbay for a medical examination , and Decker leaves the bridge . Spock orders an evasive course back to the " Constellation " . However , on the way to sickbay , Decker overpowers Montgomery , knocks him unconscious , and sneaks down to the hanger deck . On the " Constellation " , Scott reports to Captain Kirk that they now have ship ' s communications , one - third impulse power , and minimal deflector shields . Kirk plots a course and plans his rendezvous with the " Enterprise " . On the " Enterprise " , an unauthorized Class F launches before Sulu can stop the launch bay doors from opening . It is , of course , Commodore Decker , who replies to Palmer ' s repeated hails with the exhausted calm of finality . He describes his plan to pilot the shuttlecraft directly at the planet killer , sending it and himself " right down its throat . " More a suicide than a serious attack , Decker speaks of his responsibility for his crew and how he has been ready to die himself ever since their deaths . All of Matt Decker ' s masks are gone now , and as Kirk tries to talk him down and Spock preaches logic , he stares at the gaping maw of the planet killer . Closing the comm channel , Decker watches with increasing horror and panic as he approaches death , and it consumes him . With a sorrowful expression , Kirk closes his communicator and Spock , looking as emotional as he ever gets , says " " He ' s gone . " " Act Four . Spock hails Captain Kirk on the " Constellation " and offers his condolences on Commodore Decker ' s death . Kirk ' s biggest regret is that Decker died for nothing . However , Sulu reports that the ship ' s sensors have detected a slight drop in the planet killer ' s power emanations , and wonders if it could be a result of the shuttlecraft explosion . Palmer reports that the transporter is now operational , and Spock asks Kirk if he should beam them aboard . Kirk orders Spock to beam the damage control party back to the " Enterprise " , but he and Scott will remain behind . Kirk has the idea that Decker ' s method was viable ; he just didn ' t have enough power in the shuttlecraft to be effective against the planet killer . Kirk asks Spock if the 97 megaton fusion explosion that would result from an overload of the impulse engines on the " Constellation " would be enough the destroy the planet killer . Spock reminds Kirk of the device ' s neutronium hull , which no known force can penetrate . Kirk ' s plan , however , is not to penetrate the hull , but to trigger the explosion while the " Constellation " is inside the planet killer . He orders Scott to rig a thirty - second delay detonation device for the impulse engine overload , which Kirk can set off from auxiliary control . Spock reports that he can ' t tell if the explosion would be sufficient to destroy the planet killer , and warns Kirk that he is getting dangerously close to the device . Echoing Decker , Kirk says that he plans to take the " Constellation " even closer and " ram her right down that thing ' s throat , " only beaming back to the " Enterprise " at the last minute . Both Spock and Scott warn Kirk that the transporter is not operating at 100 % efficiency , and that thirty seconds is cutting the margin of safety rather close . Kirk is determined to proceed , however . Scott demonstrates the operation of the delay detonation device to Kirk , and warns him that once initiated the overload cannot be stopped , before beaming back to the " Enterprise " . He makes it back safely , but the transporter malfunctions and needs repair before they can transport Kirk . The power levels on the " Constellation " are dropping , however , and the ship is rapidly approaching the planet killer , so time is of the essence . Scott climbs into a Jefferies tube to effect repairs . The transporter is soon operational again , but only just barely . Scott doesn ' t expect his jury - rigging to last for long . When the " Constellation " is less than five hundred miles from the planet killer , Kirk activates the time delay trigger and requests beam - out . Unfortunately , the transporter shorts out again , and Kirk is trapped on the " Constellation " with no way to stop the impulse engine overload that is imminent . Scott returns to the Jefferies tube and , with Spock ' s repeated urging to hurry , completes repairs just in time for Kyle to beam Kirk out before the explosion . Kirk hurries to the bridge , arriving there to find everyone demonstrably relieved , for the planet killer is quite dead . Kirk orders a power - conserving course and the continuation of repairs and communications with Starfleet are restored . Kirk and Spock lament the death of Matt Decker , with Kirk assuring Spock that his log will say that Decker died in the line of duty . Kirk points out the irony that they ended up using a form of H - bomb , the doomsday machine of the 20th century , to destroy this alien 23rd century doomsday machine . Spock wonders if there might not be other devices like it wandering around the universe . Kirk sincerely hopes not , as he found the one they encountered to be " quite sufficient . " Memorable quotes . " " They say there ' s no devil , Jim , but there is . Right out of hell , I saw it ! " " " " Matt , where ' s your crew ? " " " " On the third planet . " " " " There is no third planet . " " " " Don ' t you think I know that ? There was , but not any more ! " " " " Bones , did you ever hear of the doomsday machine ? " " " " No . I ' m a doctor , not a mechanic . " " " " A robot weapon that purposely destroys entire solar systems . Why ? " " " Unknown , captain . However , Mister Sulu has computed the path of the machine , using the destroyed solar systems as a base course . Projecting back on our star charts , we find that it came from outside , from another galaxy . " " " What is the projected course of this thing ? " " " If it follows its present path , it will go through the most densely populated section of " our " galaxy . " " " Random chance seems to have operated in our favor . " " " " In plain , non - Vulcan English , we ' ve been lucky . " " " " I believe I said that , doctor . " " " " Spock ? Do something ! " " " " Mr . Spock knows his duty under regulations , doctor . Do you ? " " " " Aye , we can cross - connect the controls , but it ' d make the ship almost impossible for one man to handle . " " " " You worry about your miracles , Scotty . I ' ll worry about mine . " " " " If I only had some phasers . " " " " Phasers ? You ' ve got ' em . I have one bank recharged . " " " " Scotty , you ' ve just earned your pay for the week . " " " " Commodore Decker , you ' re relieved of your command . " " " " I don ' t recognize your authority to relieve me ! " " " " You may file a formal protest with Starfleet Command , assuming we survive to reach a Starbase , but you are relieved . Commodore , I do not wish to place you under arrest . " " " " You wouldn ' t dare . " " ( Spock signals the guards forward ) " " You ' re bluffing . " " " " Vulcans never bluff . " " " " Commodore , I must insist that you return to the ship ! " " " You said yourself , Spock . There is no way to blast through the hull of that machine , so . . . I ' m going to take this thing right down its throat . " " " " The commander is responsible for the lives of his crew , and for their deaths . Well , I should have died with mine . " " " " Sir , may I offer my condolences on the death of your friend . It is most regrettable . " " " " It ' s regrettable that he died for nothing . " " " " Captain , you ' re getting dangerously close to the planet killer . " " " " I intend to get a lot closer . I ' m going to ram her right down that thing ' s throat ! " " " " A cranky transporter ' s a mighty finicky piece of machinery to be gambling your life on , sir . " " " " Gentlemen , I suggest you beam me aboard . " " Background information . Remastered information . " The Doomsday Machine " was the twentieth episode of " The Original Series " to be remastered , premiering in syndication the weekend of . It was one of the most heavily enhanced episodes of the remastered series produced . There were 105 effects shots in the remastered version , in contrast to the twenty or thirty in an average episode . The " Constellation " received far more detailed damage than was previously possible , with gnarled warp coil s and exposed decks visible in certain shots . The planet killer received a major update , as did its antiproton beam . The shots of the shuttlecraft leaving the bay with Commodore Decker aboard were completely re - done . Decker lifts the shuttlecraft off the deck before the bay doors are fully open , and there is a new shot of the craft ( renumbered " 6 " ) from the exterior of the " Enterprise " . The discrepancy in relative sizes between the planet killer , the two starships , and the shuttlecraft from the original version has been adjusted . The staff of CBS Digital ( creators of the remastered effects ) played a prank on Senior FX Supervisor Niel Wray by creating a fake version of the remastered episode trailer ( with a shot of the " Constellation " relabeled as " " Consolation " " ) and a fake version of TrekMovie . com populated by fake comments ( attributed to real users of the site ) on the " mistake . " The results of the prank can be seen . Links and references . References . antimatter ; antiproton ; antiproton beam ; arrest ; atmospheric pressure ; auxiliary control ; asteroid ; bluff ; " Bones " ; Class F shuttlecraft ; coffee ; communication system ; computer system ; ; ; control circuit ; damage control ; dampening field ; debris ; deflector ; delay detonation device ; devil ; disaster beacon ; distress call ; doomsday machine ; " " ; emergency condition 3 ; English language ; evasive action ; Federation ; filtration system ; force beam ; fusion explosion ; H - bomb ; Hell ; impulse control system ; inverse phasing ; L - 370 ; L - 370 planets ; L - 374 ; L - 374 I ; L - 374 II ; L - 374 III ; L - 374 IV ; lead ; life support system ; logic ; main energizer ; Masada ; mechanic ; megaton ; microtape ; mile ; Milky Way Galaxy ; neutronium ; ; phaser bank ; planet killer ; pounds per square inch ; power cell ; power generator ; power plant ; program - defensive sphere ; radiation ; red alert ; reserve energy bank ; Rigel colony ; Rigel system ; shock ; shuttlecraft bay ; solar day ; starbase ; Starfleet Command ; Starfleet Regulations ; star chart ; starship ; subspace interference ; subspace transmitter ; suicide ; total conversion drive ; tractor beam ; trident scanner ; viewing screen ; Vulcan s ; warp drive pod ; yellow alert