Commodore Matt Decker was a Human Starfleet flag officer assigned as the commander of the USS Constellation. In 2267, the Constellation was on a routine survey mission near System L-374 when it encountered an alien doomsday machine systematically destroying the planets of the system. Decker remained on board to confront the machine, beaming his entire crew to what he believed was safety. When the alien machine destroyed that planet, and crippled the Constellation, Decker was the only survivor.