Just like in the original game, you're a nameless, silent, badass Space Marine, who has just been assigned to the Union Aerospace Corporation's base on Mars.
It has a darker tone than the rest of the series, with aspects of Survival Horror. Despite its name, it's not a sequel to the original Doom games, as much as a reboot.
Doom 3 is a 2004 First-Person Shooter in the Doom franchise, developed by id Software and released for both the PC and Xbox.