The further adventures of Riddick (Vin Diesel) continue five years later, as the escaped convict with the ability to see in the dark finds himself caught in the middle of a galactic war between two opposing forces, with the key figure being the Lord Marshal (Colm Feore), the leader of a sect called the Necromongers waging the "10th Crusade" in the 26th century.

Helping Riddick is Aereon (Judi Dench), the Ambassador of the "Elemental" race, who helps Riddick unearth the secrets of his origin and Kyra (Alexa Davalos), who has grown up since Riddick knew her as a preteen girl in the first movie.

Attempting to free himself and Kyra from a subterranean prison, Riddick ends up on board the Necromonger flagship, where he gets his chance to face off against the Lord Marshal in a battle over the future of all beings in the galaxy, both living... and dead.