The Doomsday Machine
Star-trek tos-season2-6
Season 2, Episode 6
General Information
Series Star Trek
Air date October 20, 1967
Written by Norman Spinrad
Directed by Marc Daniels
Episode guide
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Star Trek episodes


The USS Enterprise encounters the derelict hulk of the USS Constellation adrift among the remnants of a devastated planetary system. The grief stricken and guilt ridden sole survivor, Commodore Matt Decker informs them that the Constellation, and the surrounding planets, fell victim to a massive Doomsday Machine!

But when Kirk is busy directing repairs on the Constellation, the revenge obsessed Decker seizes command of the Enterprise and orders them to pursue and destroy the Doomsday Machine no matter the cost!

Plot Summary

Stardate: 4202.9 The crippled remains of the USS Constellation The crippled remains of the USS Constellation

The USS Enterprise discovers a star system where several previously identified planetary bodies have been reduced to debris. Soon they receive a distress call from another Federation vessel, the USS Constellation, incapacitated and adrift. Captain Kirk, Chief Medical Officer Dr. McCoy, Chief Engineer Montgomery Scott, and a damage control team beam aboard to investigate. Commodore Decker is the sole survivor Commodore Decker is the sole survivor

Mr. Scott reports that the Constellation's warp drives are irrepairible, and the weapons are exhausted. They soon find the Constellation's sole survivor, its commanding officer, Commodore Matt Decker, alive but in a state of shock in the auxiliary control room.

Decker tells Kirk that the destruction was caused by a giant robotic device; he describes it as being, "miles long, with a maw that could swallow a dozen starships. It destroys planets, chops them into rubble", and says that when it attacked the Constellation he ordered the crew to abandon ship. He beamed the entire crew down to the planet's surface below, only to witness the robot consume the planet, resulting in their deaths.

Mr. Spock believes that the machine grinds up and consumes planets for fuel, and given its trajectory, it probably originated outside the galaxy, and is headed on a path toward the "most densely populated region of our galaxy."

Kirk thinks they are dealing with a 'doomsday machine', a weapon of such awesome destruction that it was probably intended as a deterrent, not to be actually used, but was somehow activated. It destroyed its creators long ago but continues on indefinitely, fueled by the planets it destroys. Kirk orders Decker and McCoy back to the Enterprise while he and Scott remain aboard the Constellation. The dreaded 'Doomsday Machine' is sighted The dreaded 'Doomsday Machine' is sighted

Meanwhile, the Enterprise crew goes on alert as the Doomsday Machine turns on them, generating interference that makes communication with Starfleet. Decker citing Starfleet regulations, relieves Mr. Spock of command, and orders a frontal assault on the Machine in spite of Spock's warning that the Enterprise's phasers are useless against the Doomsday Machine's neutronium hull. In the resulting confrontation, the Enterprise is disabled and ensnared by a tractor beam pulling it toward the destructive interior of the Doomsday Machine.

When Mr. Scott restores impulse and phaser power to the Constellation, Kirk fires on the Machine to release its hold on the Enterprise. As it veers away, Kirk assumes responsibility for ordering Spock to relieve Decker of command of the Enterprise. Decker relents when it becomes clear that the bridge security will take Spock's orders over his own. On the way to to sickbay, Decker incapacitates his escort and commandeers a shuttlecraft on a suicide mission to destroy the Doomsday Machine. Kirk pilots the Constellation on its final mission - into the heart of the 'Doomsday Machine' Kirk pilots the Constellation on its final mission - into the heart of the 'Doomsday Machine'

The explosion of the shuttlecraft momentarily decreases the power of the Doomsday Machine, which inspires Kirk to have Mr. Scott rig the Constellation to explode with a 97.835 megaton blast and pilots it into the Doomsday Machine, ordering Spock to beam him back to the Enterprise once the 30 second fuse has been set.

Once the Constellation is rigged, all personnel, save Kirk, are beamed back to the Enterprise, but when it comes time to beam Kirk back, the transporter fails. Kirk is stuck on the Constellation as the last few seconds tick by while Mr. Scott tries to effect repairs. Scott's desperate fix finally succeeds, and in the final second Kirk is beamed aboard just as the Constellation explodes, destroying the Doomsday Machine, leaving it a lifeless hulk drifting through space.

Kirk suggests that this may be the first time a Doomsday Weapon was used to destroy another doomsday weapon.

Production Notes

This episode was written by acclaimed science fiction writer Norman Spinrad, with D.C. Fontana as a script consultant, based on a novella he had written called 'The Planet Eater' which had been rejected by his publisher.

The episode was written with Robert Ryan in mind for Decker, but Ryan was unavailable at the time of production.

Unlike most of the second season episodes, the music for 'The Doomsday Machine' was created by Sol Kaplan, as a direct score for the episode instead of laid in from existing tracks. The episode was nominated for a Hugo Award for 'Best Dramatic Presentation', at the 1968 World Science Fiction Convention.

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