Star Trek (1967): S02E06 – The Doomsday Machine


“The Doomsday Machine” is the sixth episode of the second season of the American science fiction television series Star Trek.

Written by Norman Spinrad and directed by Marc Daniels, it was first broadcast on 20 October 1967.

In the episode, the starship Enterprise fights a powerful planet-killing machine from another galaxy.


The Federation starship Enterprise, following a trail of mysteriously destroyed star systems, picks up the automated distress beacon of one of the Enterprise’s sister ships, the USS Constellation. Upon arrival, the Constellation is found heavily damaged and drifting in space; Captain Kirk, Chief Medical Officer Dr. McCoy, Chief Engineer Scotty, and a damage control team transport to the ship to evaluate her. There they discover the only member of the crew still aboard: the ship’s commander Commodore Matt Decker, who is suffering from severe mental shock.

After McCoy injects him with a sedative, Decker explains that he and his crew had discovered a giant machine, miles long, that used beams of antiprotons to tear planets apart, consuming the rubble for fuel. The attack by the Constellation on the machine was ineffective and the ship suffered heavy damage. Decker evacuated his crew to one of the planets of the system, which the machine subsequently destroyed. Kirk theorises that the machine is an ancient doomsday machine, which must be stopped before it reaches more populated sectors of the galaxy. McCoy and Decker transport to the Enterprise which has taken the Constellation in tow, while Scott’s damage control team attempt repairs on the Constellation’s damaged impulse engines, weapons and shields. Kirk attends to the Constellation’s nonfunctional viewscreen, which, other than communications from Enterprise, will be his only means of monitoring events outside the ship.

The Enterprise’s first officer, Spock, informs Kirk of the sudden appearance of the so-called planet killer and it begins to pursue the Enterprise. As the boarding party prepares to beam back aboard, the machine attacks the Enterprise, damaging the transporter and disrupting communications. Decker, now the senior officer on the Enterprise, assumes command and orders a phaser attack. The phasers are useless against the machine as its hull is constructed of solid neutronium, and the ship is then caught in a tractor beam which draws it towards the planet killer’s maw. Kirk completes his repair of Constellation’s viewscreen and is shocked to see the Enterprise engaging the machine. Scott has managed to repair impulse engines and recharge one of the Constellation’s phaser banks, so Kirk uses the crippled ship to approach and fire at the planet killer, distracting it long enough for Enterprise to escape its tractor beam. After repairing the transporter and reestablishing voice communications, Enterprise retreats to a safe distance. Spock relieves Decker of command on Kirk’s orders and Decker is escorted to Sickbay. However, Decker subdues his security escort and steals a shuttlecraft. Overcome with guilt because of the loss of his crew, Decker informs Spock he is flying the shuttlecraft straight into the maw of the machine. Despite Kirk’s plea for him to return to the Enterprise and his own horror as he is swallowed by the planet killer, Decker does not deviate from his course and dies.

Lt. Sulu reports that the shuttlecraft explosion has reduced the planet killer’s power output by a small amount. Realising that this may have been Decker’s intention, and hoping that a starship would do much more damage, Kirk comes up with a plan to explode the Constellation inside the planet killer. Over Spock’s objections, Kirk insists on piloting the damaged starship himself, and Scott rigs the impulse engines to explode with a thirty-second delay before detonation, warning his captain that once the timer is enabled, there is no way to abort it.

With the rest of the boarding party transported back to the Enterprise, Kirk aims the Constellation at the maw of the planet killer, triggers the timer, and orders the Enterprise to beam him aboard. The transporter malfunctions, and Scott races to set it right with advice from Spock. With virtually no time to spare, Kirk is safely beamed aboard the Enterprise as the Constellation explodes inside the planet killer, leaving it dead in space, its threat ended.

Star Trek TV Series

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Production & Filming Details

  • Director(s): Marc Daniels.
  • Writer(s): Norman Spinrad.
  • Production: Desilu Productions (1966-1967) and Paramount Television (1968-1969).
  • Distributor(s): Paramount Pictures (1966-2006), CBS Paramount Television (2006-2007), and CBS Television Distribution (2007-Present).
  • Original Network: NBC.
  • Release Date: 20 October 1967.
  • Running Time: 50 minutes.
  • Country: US.
  • Language: English.

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