Dr. Patrick Cory has been experimenting on keeping alive the brain of a dead monkey. A plane crashes nearby and on that plane is the ruthless millionaire William Donovan. Dr. Cory sees this as an ideal opportunity to put his skills to the test on a human brain.

Through telepathy, he succeeds in communicating with Donovan's brain but before long it starts to take over his whole mind. His wife and son both try to help, but with disastrous consequences.