Insurgents shoot down British fighter pilots Captain Kate Sinclair and WSO Terry Johnson over Afghanistan. Engaged in a firefight once on the ground, the insurgents kill Johnson while Kate flees to an old Russian bunker hidden underground. The insurgents pursue Kate into a secret laboratory where stray gunfire inadvertently releases feral creatures from stasis chambers. As the monsters attack, Kate escapes back to the surface with a friendly insurgent named Kabir.American soldiers find Kate and Kabir and take them back to their base camp. The camp's commander, Major Roy Finch, dismisses Kate's claims of creatures, but confiscates microfilm she recovered from the lab and calls in to HQ. Kate meets other soldiers who include Sergeant Tom Hook, Corporal Kip Wilks, Corporal Jade Lafayette, Private Dwayne Everett, Private Eddie Serano, Private Tucker O'Neill, and British soldiers Sergeant Oswald Jones, Trooper Dave Bromhead, and Trooper Vince Hughes.Having tracked Kate, escaped creatures descend on the camp after nightfall. As chaos ensues, the monsters slaughter Serano, Everett, O'Neill, and Hughes. Following several violent encounters with the creatures, Kate, Kabir, Hook, Finch, Wilks, Lafayette, Jones, and Bromhead regroup inside a shipping container to wait out the nighttime attack.With the creatures having retreated at daybreak, Wilks examines a carcass left behind and determines that sunlight can hurt the beasts. Finch further reveals that Army Intelligence informed him that Russians who retrieved alien DNA from a downed spacecraft and spliced it with humans secretly created the creatures, and the Afghan invasion was actually a cover-up to retrieve the monsters for use as bio weapons.The carcass suddenly reanimates and attacks Kate with tentacles that briefly take over her mind. Finch sacrifices himself to blow up the creature with a grenade.Kate, Kabir, Hook, Wilks, Lafayette, Jones, and Bromhead mount a mission to destroy the underground bunker. Wilks remains outside to operate a Humvee's winch so the others can descend into the bunker through an elevator shaft.Creatures capture Hook, but Kate leads the effort to rescue him. The soldiers discover the Russian experiments were even wilder than previously thought when they find a tank containing a massive monster. As action spreads throughout the subterranean facility, a creature bites off Lafayette's face. Jones blows himself up to take out a horde of monsters. A creature thrusts its claw through Bromhead's skull. Kabir realizes one of the humanoid beasts is his mutated father just before the elevator pulls down the Humvee on top of them. Meanwhile, Wilks tries fighting off insurgents outside.Kate and Hook make it back to the surface and rescue Wilks. The three surviving soldiers quickly race away from the area in time to avoid a bomb dropped on the bunker. Kate, Hook, and Wilks realize a secret cabal in the military is still trying to gain control of the creatures. (thanks to culturecrypt)