When a group of medical residents get caught experimenting with illegal substances, their plan to save face and save their futures develops disastrous and deadly consequences. They get the only witness to their drug use, a lonely outsider (Andrew Lee Potts), to join in. When he overdoses and winds up in a coma, one of the doctors-in-training (Arielle Kebbel) tries to do the right thing and heal him. But the drug cocktail she gives him has side effects no one could expect, giving him the ability to possess other people and act out his will. And now, he's bent on revenge and ready to make the hospital staff pay for what's happened to him.