Aliens vs. Predator: Requiem (also known as AVP:R) is a 2007 American science-fiction horror film directed by the Brothers Strause (Colin and Greg) and written by Shane Salerno. A sequel to 2004's Alien vs. Predator and the second of the two-part Alien vs. Predator prequel series to the Alien franchise, it continues the film crossover of the Alien and Predator media franchises. The film's lead roles are played by actors Steven Pasquale and Reiko Aylesworth.
Following the events of Alien vs. Predator, a Predator spaceship is leaving Earth carrying dead Aliens, living facehuggers, and the body of the Predator that defeated the Alien queen. A chestburster erupts from the dead Predator's body; it is a new creature that is a hybrid of Alien and Predator characteristics. It quickly matures into an adult and begins killing Predators throughout the ship. A Predator's weapons fire punctures the hull and the ship crashes in the forest outside of Gunnison, Colorado.
With the Predators dead, the hybrid and several facehuggers escape, implanting embryos into a nearby father and son and into several homeless people living in the sewers. A distress signal from the wrecked ship reaches the Predator home world and a lone Predator responds, traveling to Earth to observe the cause of the crash and track the facehuggers. It begins to erase the evidence of the Aliens' presence by destroying the crashed ship and using a blue liquid to dissolve the bodies of the facehuggers and their victims.
Meanwhile, ex-convict Dallas Howard (Steven Pasquale) has just returned to Gunnison after serving time in prison. He is greeted by Sheriff Eddie Morales (John Ortiz) and reunites with his younger brother Ricky (Johnny Lewis). Ricky has a romantic interest in his more affluent classmate Jesse (Kristen Hager) and is being harassed by her boyfriend Dale (David Paetkau) and two of his friends. Kelly O'Brien (Reiko Aylesworth) has also just returned to Gunnison after service in the military, and reunites with her husband Tim (Sam Trammell) and daughter Molly (Ariel Gade).
The Predator fights a number of Aliens in the sewers, and as the battle reaches the surface several of them disperse into the town. The Predator pursues some to the power plant, where collateral damage from its weaponry causes a city-wide power outage. Ricky and Jesse meet at the high school swimming pool but are interrupted by Dale and his cohorts just as the power fails and an Alien enters the building, killing Dale's friends. Another Alien invades the O'Brien home, killing Tim while Kelly escapes with Molly.
Kelly, Molly, Ricky, Jesse, Dale, Dallas, and Sheriff Morales meet at a sporting goods store to gather weapons. Troops from the Colorado Army National Guard arrive but are quickly killed by the Aliens. When the battle between the Predator and the Aliens enters the store, Dale is killed and the Predator's shoulder cannons are damaged; it is able to modify one into a hand-held blaster.
As the survivors attempt to escape Gunnison, they make radio contact with Colonel Stevens (Robert Joy) and learn that an air evacuation is being staged at the center of town. Kelly is suspicious of the military's intentions, convincing a small group to go to the hospital where they hope to escape by helicopter, while Sheriff Morales heads to the evacuation area with the rest of the surviving citizens. The hospital, however, has been invaded by Aliens and the hybrid. The Predator soon arrives and in the ensuing battle, Jesse is killed, Ricky is injured, and Dallas takes possession of the Predator's blaster cannon.
As the battle reaches the rooftop, Dallas, Ricky, Kelly, and Molly escape in the helicopter while the Predator battles the hybrid hand-to-hand. The two creatures mortally wound each other just as a military jet arrives; rather than a rescue airlift it is a bomber, executing a tactical nuclear strike that destroys the entire city and kills all of the extraterrestrials along with the remaining citizens. The shock wave causes the fleeing helicopter to crash in a clearing, where the survivors are rescued by the military. The Predator's blaster cannon is confiscated, and Colonel Stevens presents it to Ms. Yutani.
- Steven Pasquale as Dallas Howard, a recently-released convict who returns to Gunnison and reunites with his brother, Ricky.
- Reiko Aylesworth as Kelly O'Brien, a soldier who returns to her family in Gunnison from military service.
- John Ortiz as Edward "Eddie" Morales, the sheriff of Gunnison.
- Johnny Lewis as Richard "Ricky" Howard, a high school student and younger brother of Dallas.
- Ariel Gade as Molly O'Brien, daughter of Kelly and Tim O'Brien.
- Sam Trammell as Timothy "Tim" O'Brien, husband to Kelly and father of Molly.
- Kristen Hager as Jesse, a classmate of Ricky Howard who begins to show interest in him, angering her boyfriend Dale.
- Robert Joy as Colonel Stevens, commander of the military forces attempting to contain the Alien infestation.
- David Paetkau as Dale Collins, Jesse's boyfriend who bullies Ricky.
- Ian Whyte as the Predator / Wolf, one of the film's titular alien species. The main Predator of the film comes to Earth in order to eliminate the Aliens and all traces of their presence. This Predator was nicknamed "Wolf" by the production team, after Harvey Keitel's character in Pulp Fiction whose role is also that of a "cleaner". Whyte had previously portrayed the Predator in Alien vs. Predator. Additional Predators in the film's opening scene were played by Ian Feuer and Bobby "Slim" Jones.
- Tom Woodruff, Jr. as the Aliens / Predalien, the other titular species of the film. Having previously portrayed the Aliens in Alien 3, Alien Resurrection and Alien vs. Predator, Woodruff reprised the role for Aliens vs. Predator: Requiem. He also portrayed the Alien/Predator hybrid creature, dubbed the Predalien by the production team.
- Gina Holden as Carrie, a waitress.
- Chelah Horsdal as Darcy Benson, wife of the father and son hunting pair who go missing in the woods.
- David Hornsby as Drew, a pizza parlor supervisor.