Watch Sergeant Deadhead
An experiment with the space program involving a man and a chimp is turned topsy-turvy. A turn of events occurs sometime between the launch and return of the ship back to Earth. When scientists and doctors examine the chimp, they find that he has taken on the brain of the astronaut. The reverse happens to the astronaut and there may not be a way to get them back to normal. The scientists and doctors must work overtime to find a cure for the problem.