| “ | They say there's no devil, Jim, but there is, right out of Hell. I saw it! | „ |
| ~ Decker, describing the Planet Killer to Kirk |
Matthew "Matt" Decker was a human introduced in the Sar Trek episode The Doomsday Machine.
He was portrayed by the late William Windom.
A member of the Federation Starfleet Decker was the husband of Joan, and the father of Starfleet officer Willard Decker. He was a friend of James T. Kirk. By 2256 Decker was one of the most decorated Captains in Starfleet history, along with Robert April, Jonathan Archer, Philippa Georgiou, and Christopher Pike.
In 2267, Decker was a Starfleet Commodore, in command of the Constitution class starship USS Constellation (NCC-1017). Encountering a star system where planets were in the process of breaking up, Decker had his ship investigate and found the Planet Killer destroying the planets. The device attacked his ship, and left the Constellation dead in the water. Decker beamed his crew down to the third planet in the L-374 system. Another attack disabled the transporter before he could join them, and Decker's crew died when the Planet Killer destroyed the third planet.
The USS Enterprise arrived to investigate, and rescued Decker from the wreck of the Constellation. When the Planet Killer came back into the system, Decker took command of the Enterprise from Spock and attacked the Planet Killer. The Enterprise was nearly destroyed in the attack before Kirk was able to use the Constellation to distract the Planet Killer.
Kirk then ordered Spock to relieve Commodore Decker. While being escorted to sickbay, Decker overpowered his escort, and stole the shuttlecraft Einstein. Decker flew the shuttle into the Planet Killer, and died when the shuttle exploded. The explosion caused minor damage to the Planet Killer.
Through his death, Decker demonstrated that an exploding ship would cause damage and possible destroy the internal workings of the Planet Killer. Kirk flew the Constellation into the Planet Killer. Barely escaping in time, Kirk went to the bridge to find the explosion had disabled the Planet Killer.
Kirk deliberately kept the ship's log vague on Decker's final actions, merely stating that Decker heroically died in the line of duty. He informed Joan and their son of Decker's death.
