Left for dead on a sun-scorched planet, Riddick finds himself up against an alien race of predators. Activating an emergency beacon alerts two ships: one carrying a new breed of mercenary, the other captained by a man from Riddick’s past.

The wanted criminal Richard Bruno Riddick (Vin Diesel) arrives on a planet called Helion Prime and finds himself up against an invading empire called the Necromongers, an army that plans to convert or kill all humans in the universe.

Strange happenings occur on a WW II submarine.