At the Universität Zürich Institut Für Medizin in Sweden, colleagues break down the door to Dr. Hans Gruber’s laboratory, and find his student, Herbert West, standing over Gruber’s shaking body, holding a syringe filled with a glowing green substance. The doctor’s head explodes, and Herbert is accused of killing him, but the student claims to have given him life. Sometime later, at the Miskatonic Medical School in Arkham, Massachusetts, medical student Dan Cain attempts to revive a patient with cardiopulmonary resuscitation (CPR), but his colleagues insist the woman is dead, and he should give up. Dan takes the body to the hospital morgue, and is introduced by Dean Halsey to new transfer student, Herbert West. When Herbert meets Dr. Carl Hill, he accuses the professor of plagiarizing Dr. Gruber’s work, and calls Hill’s theory about the brainstem remaining alive for six minutes after death “outdated.” Meanwhile, Dan Cain posts a notice seeking a roommate, and returns home to have sex with his fiancée, Megan Halsey, the dean’s daughter. She worries that her old-fashioned father will discover her active sex life, and promises to marry Dan as soon as he graduates. Herbert West arrives, unannounced, in response to the roommate advertisement, and surprises Dan and Megan. After touring the house and basement, Herbert offers Dan cash to move in immediately. Megan is alarmed by his odd behavior, but Dan accepts his offer. The students attend Dr. Hill’s class and watch as he removes the brain from a corpse. Herbert causes a scene, and insults the professor again. That evening, Dean Helsey invites Dr. Hill to his home and toasts him for receiving an award for a medical invention. Dr. Hill makes a suggestive remark to Megan, making his interest in her clear. Later, Megan expresses her dislike of Herbert to Dan. When Dan’s cat, Rufus, goes missing, Megan searches Herbert’s bedroom and discovers the dead cat in his mini-refrigerator. Herbert arrives, and Megan accuses him of killing the pet, but he claims to have found the animal dead. Dan inquires about the strange, glowing liquid in Herbert’s possession, and is told to mind his own business. Later, Dan is awakened by sounds in the basement, and finds Herbert being attacked by Rufus, who has come back to life. The young men fight the rabid cat, and Dan kills the creature by throwing it against the wall. Afterward, Herbert shares his re-animation theory, and reveals his “re-agent” serum. He asks Dan for his help, and to prove that it works, injects it once again into the mutilated feline, which twitches back to life. Megan arrives and is shocked to see what they have done. Later, Dan excitedly reveals Herbert’s discovery to Dean Halsey, but Halsey threatens to take Dan’s student loans away if he continues with the re-animation experiments. Regardless, Dan and Herbert sneak into the morgue and inject a corpse with the serum. The dean warns Megan to stay away from Dan, and discovers that the young men are in the morgue. Dan and Herbert believe the serum has failed, but the corpse returns to zombie-like life, and attacks them. As Dean Halsey arrives, the corpse breaks down the door and attacks him. Herbert uses a bone saw to kill the creature. They discover that the dean has died, and Herbert insists they experiment on his “fresh” corpse, injecting the dean with the re-animation serum. Megan enters, unaware of what the young men have done, and witnesses her crazed father choking Dan and Herbert. His colleagues assume the dean has gone insane, and lock him up in a straitjacket. When Dr. Hill asks Megan to sign a release allowing him to experiment on her father, she reluctantly agrees. Sometime later, Dan confesses the truth to Megan: that her father is actually dead. Elsewhere, Dr. Hill visits Herbert in his basement laboratory, and reveals his knowledge of the dean's demise. Fearing imprisonment, Herbert shares his research and serum. However, as Dr. Hill looks through a microscope, Herbert attacks him with a shovel, beheads him, and injects Dr. Hill’s severed head and body with the serum. Herbert places the head on a tray, and takes notes on the experiment. Dr. Hill’s headless body slams Herbert’s head into a table, and knocks him unconscious. Elsewhere, Dan and Megan visit her father, and discover that Dr. Hill has performed a lobotomy on him with a laser beam. The subdued dean cowers in the corner. Dan finds a file that Dr. Hill kept on Megan, containing pieces of her hair, and indicating his obsession with the young woman. When Herbert regains consciousness, Dr. Hill’s head and body are gone, and his serum and notes are missing. Dan returns home, and Herbert confesses to Dr. Hill’s murder and re-animation. Meanwhile, Dr. Hill goes to his office and injects himself with more serum, increasing his cognitive ability. He releases Dean Halsey, and orders him to kidnap Megan, then returns to the morgue where he injects several corpses with the serum. Worried about Megan, Dan checks on her at home. After a tearful reconciliation, the couple is attacked by Dean Halsey. He takes his daughter’s unconscious body to the morgue where Dr. Hill straps her naked to a table, and begins molesting her breasts. Megan regains consciousness, and screams as Dr. Hill’s body picks up his head and holds it to her ear, grunting his desire. He licks her face, and with the help of his hands, continues moving further down her body. Herbert arrives and confronts Dr. Hill, while Dan frees Megan from the straps. However, the re-animated corpses come to life and attack the students. To tame and control the zombie-like creatures, Dr. Hill previously performed lobotomies on their reanimated corpses, and they obey his command. Dr. Hill captures Herbert, and begins to perform a laser lobotomy on him. Megan tries to reason with her father, and after he finally recognizes her, he turns his attack on Dr. Hill, crushing his detached head. Meanwhile, Herbert injects Dr. Hill’s headless body with an overdose of serum, causing the intestines to spring from his disintegrating body, and wrap themselves around Herbert. Before he succumbs to strangulation, Herbert throws his research and remaining serum to Dan and Megan. The couple flee to an elevator, but Megan is choked by a corpse. Dan chops off the creature’s hand, and performs CPR to resuscitate her. He takes her limp body to an operating room in the hospital, where his colleagues assist him. Dan uses electric paddles to shock Megan’s heart, but when she remains unresponsive, his colleagues stop his efforts. He kisses Megan goodbye before remembering that he has Herbert’s serum. Professing his love, Dan injects her brainstem with the glowing liquid. Megan lets out a scream in the darkness.