naked zombie body. A mosquito trapped in the room bites Bart, who attempts to pose with the corpse. Fearing contamination but unwilling to execute Bart, Henson handcuffs Bart to a radiator, and the two soldiers exit the room, falling back to the van. Meanwhile, the second team, including Alex and Ellis, are attacked multiple times. Eventually, every soldier escorting them is killed, including the unit's leader, Sergeant Griffin. They fight their way to the professor's laboratory, finding the original specimen still imprisoned and a pair of students, Lonny and Sarah, who had survived. They enter the confinement room and extract blood from the zombie but are forced to kill it when it breaks free. Lonny and Sarah, who had allowed them into the confinement room, are overrun and torn apart by zombies, and Alex and Ellis escape while the zombies feed on the bodies. Henson and Rodriguez make it to the extraction vehicle. There, they prepare to rescue Alex and Ellis, but a zombie who was locked in the back of the van by the soldier assigned to guard it bites Rodriguez. Henson executes Rodriguez, and the duo arrives in front of the science building as Alex and Ellis fight their way through a zombies horde. Henson saves Alex and Ellis but destroys the blood vial sample. They are forced to turn back, with ten minutes before the military releases the missile level the campus, and fight their way back to the confinement room. They retrieve a second vial, but Henson is bitten on the ankle. She remains behind and commits suicide as Alex and Ellis escape before the missile strikes the campus. Only Ellis makes it out before the missile hits, with Alex surrounded by zombies. Bart breaks free from the dormitory by amputating his hand and forces Ellis to hand over the vial. Bart decides to kill Ellis anyway, but Alex, having survived, kills Bart. His dying action is to pull the pin on a hand grenade, destroying the vial. Alex is wounded but uncertain of her condition. Ellis refuses to execute her. The two leave together as they head to Seattle, finding that the infection has spread to the rest of the city. In a post-credits scene, the infected professor from the school breathes heavily and looks frantically around. Cast Emmanuelle Vaugier as Dr. Alexandra / Alex "Nightingale" Morgan Ed Quinn as Lieutenant Jake Ellis Sticky Fingaz