Isolation (2005 film)

Dan Reilly, a farmer working in rural Ireland, is propositioned by a local bio-genetics firm to assist in some experiments to make faster-growing cattle. The firm sends Orla, a veterinarian, to inspect the cows to ensure the experiment is running smoothly. While performing a palpation, Orla is bitten by the unborn calf. She informs John, a genetic scientist from the firm, who comes to the farm and performs another inspection. Orla shows him her bite wound and suggests terminating the calf, but John assures her the calf is normal and that her injury was merely muscle pressure from the cow. John also informs Dan of a trailer parked near his farm and reminds him that the experiment is supposed to be kept secret from the public. Dan goes out and speaks to the inhabitants, traveler Jamie and his girlfriend Mary, and tells them they must leave by morning.

That same night, Dan goes to check on the pregnant cow and finds that she has gone into labor and is bleeding profusely. Dan finds he is unable to pull the calf out. Desperate, he goes back to the trailer and asks Jamie for help. Together, they successfully birth the calf. When Dan starts inspecting the newborn calf, it bites him. As thanks for their help, Dan allows Jamie and Mary to stay on his farm.

Orla later returns to inspect the calf. When Dan tells her that the calf bit him, she checks its mouth and discovers that it has fangs. Orla decides to terminate the calf with a cattle gun, but it survives the shot to its head and begins to scream, which causes its mother to become aggressive. Orla kills both the mother and the calf. She performs an autopsy on the calf and discovers that it was pregnant. She pulls out six fetuses, all of which are extremely deformed and have their skeletons growing outside their bodies. Dan and Orla begin to argue and fail to notice that one of the fetuses is still alive and crawls away. Orla drives off after warning Dan of the possibility of infection.

The next morning, Mary tends to Dan's injured hand and Jamie offers to feed the farm animals. When Jamie goes to feed the other pregnant cow in the barn, he notices that it has several wounds on its lower body. While walking through shallow water in the barn, he is bitten by something in the water. Jamie then spots a police car arriving at the farm and hides. The officer notices Mary and begins questioning her, but Dan assures him that she has permission to stay. The officer then questions Dan about Orla, who is missing, but Dan states that he hasn't seen her since last night. After the officer leaves, Dan goes back to the barn and finds Orla's jacket near the corpse of the mother cow, which looks to have been autopsied. Dan burns the carcass to prevent anything from spreading to his other cows.

Later that night, John returns and demands to see the mother cow. When he learns that it had been killed and burned, he goes to the lab and finds the calf carcass and the malformed fetuses. Upon inspecting the cells of one of the fetuses, he finds that they are replicating extremely quickly. Meanwhile, Jamie and Mary are having sex in their trailer, during which Jamie acts strangely. When Mary asks him, he apologizes and states that he hasn't been feeling well. They both go to sleep, but Mary is awakened by a small creature crawling in their bed. John later informs them that the creature they saw was the escaped fetus and that it has the potential to infect other cows and cause a mass outbreak of the creatures. He quarantines the farm.

They begin searching for the creature but find that it is hiding in the murky water that is flooding the farm. Dan suggests driving a tractor through the water to scare it out but the tractor breaks down and he is forced to walk through the water to get back. While walking, he finds Orla's body in the water. John takes her body to the lab and finds a large wound on her abdomen. He inspects some material collected from the wound and finds the same extreme cell growth as before, but now also containing human cells. He extracts some of his own blood and adds it to the mix and is shocked to find that the mutant cells are corrupting his own. He realizes that humans can also be infected. Jamie realizes he is infected and attempts to leave the farm, but John kills him with a cattle gun. Hearing the noises outside, Dan and Mary go to investigate and find that John has killed and cut open nearly all the cows on the farm. John explains that the creature has been hiding inside the cows like a parasite, eating them from the inside and growing larger.

John then goes after the last remaining cow: The pregnant cow in the barn. He kills it but finds that it had already given birth. An argument breaks out and Mary sees John kill Dan with a cattle gun. While trying to escape, she finds Jamie's body in the barn. When John finds her, he is attacked by the now larger creature and is mauled to death. Mary flees and runs into Dan, who is still alive. They begin searching for the creature and the missing calf to stop the infection from leaving the farm. They spot the creature moving under the floorboards and Dan attempts to give chase, but is too injured, so Mary offers to go instead. She finds the calf just as new creatures begin rupturing out of its body. Mary euthanizes the calf and then begins killing the newborn creatures. The larger creature then appears and chases her but Dan turns on the machinery in the farm and then creates noise to draw the creature away from Mary. The creature attacks and begins mauling Dan, but Mary shatters a canister above them, spilling boiling water on the creature. The creature attempts to escape but Mary chases it and knocks it into active machinery, injuring it. She then beats it to death with a metal pole. She helps Dan into a car and tries to drive him to a hospital but Dan reminds her that he's infected and cannot leave the farm. Shortly after, he dies from his injuries. Bloody and shaken, Mary leaves the farm on foot.

Four months later, a pregnant Mary is at the hospital receiving an ultrasound. The doctor assures her that her baby is completely normal and healthy. Mary lets out a sigh of relief and looks out the window. As the camera zooms into the ultrasound screen, the faint outline of a creature can be seen.

• Essie Davis as Orla, a vet assisting John
• Marcel Iureș as John, the scientist working with the cattle
• Crispin Letts as the Doctor in St Thomas's Hospital, Birmingham
• John Lynch as Dan, owner of the farm
• Ruth Negga as Mary, a traveller, Jamie's girlfriend
• Stanley Townsend as Garda Sergeant Hourican
• Sean Harris as Jamie, a traveller, Mary's boyfriend