A star system whose outer planets were carved up by the planet killer in 2267, and where the Enterprise found the crippled USS Constellation drifting with only Commodore Matt Decker aboard.
System L-374 is the setting of the original series episode The Doomsday Machine. Following a trail of shattered solar systems, including neighbouring L-370 where all seven planets had been reduced to rubble, the Enterprise arrives to find that only the two innermost worlds of L-374 survive.
Adrift among the debris is the USS Constellation. Her commander, Matt Decker, had beamed his crew down to the third planet for safety when his ship was disabled, only to watch helplessly as the automated planet killer destroyed that world and everyone on it.
The machine then sets off towards the densely populated Rigel colonies. Kirk ends the threat inside the system by sending the wrecked Constellation down its maw and detonating her impulse engines.