In the distant future, the transport ship Hunter-Gratzner passes through a comet tail while on autopilot with its crew and passengers in cryo-stasis chambers. The comet debris cloud ruptures the hull, killing some of the crew. The rest of the crew, including docking pilot Carolyn Fry and her co-pilot Greg Owens, attempt to land the ship on a nearby planet. Fry tries to dump the passenger section of the ship to reduce their weight and give her a better chance of landing. Owens stops her from doing it but is killed when the ship crash lands. Fry joins the surviving ten passengers, among them an Imam, a law enforcement officer named William J. Johns, and a young boy named Jack. Johns was tasked with escorting escaped prisoner Richard B. Riddick back to prison.
The group gathers up supplies and begins exploring their surroundings. Tension runs high after Riddick escapes and Johns warns everyone that Riddick may kill them all. The group soon notices that the three suns surrounding the planet keep it in perpetual daylight, and they begin searching for water. One of the survivors goes missing, and while searching for him Fry accidentally discovers photosensitive creatures underground that are swift hunters. The group decides to walk across the desert looking for water and supplies. They come across an abandoned geological research settlement, with supplies of water and an emergency dropship with drained batteries. In the coring room at the settlement they discover more creatures, and one of Imam's children is killed. The group also discovers a model showing that very soon the planet will be eclipsed for an extended period of time and the creatures will be free to hunt above ground. Riddick rejoins the group and they all agree to go back to the crash site and retrieve the power cells from the downed ship, which will then be used to power the escape ship. Riddick talks to Fry privately and reveals that Johns is actually a drug addicted mercenary.
The group reaches the wreckage to collect the power cells, but the eclipse begins before they can return to the settlement. The creatures begin pouring out of the ground, killing another survivor. The rest of the group holes up in the wreckage and plans their next move. Inside, the creatures kill another of Imam's kids. The group decides to salvage any light source they can and create a caravan to return to the dropship. Riddick agrees to lead them since he can see in the dark. After Imam notices they have crossed their own tracks, the group stops and Riddick reveals that the creatures hunt by blood and that Jack is bleeding. The others don't understand until Riddick reveals that Jack is a female and her menses scent has attracted the creatures. Johns pulls Riddick aside and offers him a deal; if Riddick kills Jack and uses her as bait to lure the creatures away, Johns will report that Riddick died in the crash and let him go. Instead, Riddick severely wounds Johns and uses him as the bait. The others make a run for it, but only Fry, Jack, Riddick, and Imam make it to a cave near the ship. Riddick seals them in with a large stone and takes the power cells to the settlement. Inside the cave their light goes out but they discover bio-luminescent worms, which they stuff in bottles to use as light. Fry leaves the cave and finds Riddick powering up the ship to leave without them. She pleads with him to help her rescue Imam and Jack, but instead he offers to take her with him. Finally Fry convinces Riddick to go back and they retrieve Imam and Jack and take them to the ship. Fry is killed by the creatures but the others manage to flee the planet. In orbit, Riddick tells Jack to say that Riddick died on the planet below.