Veteran actor Lew Ayres, best known to many old movie buffs as 'Dr Kildare', plays Cory, a scientist experimenting with monkey's brains, seeing if it is possible for them to exist outside the body. He is assisted in his innovative work by his devoted wife Janice (the future Nancy "Just Say No" Reagan), and his alcoholic surgeon sidekick Schratt ('Shock Corridor's Gene Evans, in the film's best performance). A plane crashes near their laboratory, and the only survivor is taken there as it isn't thought he will live long enough to make it to the nearest hospital. Unable to save the man, Cory decides to secretly preserve the brain. The man is soon revealed to be ruthless multi-millionaire businessman Donovan. Cory's gamble pays off and the brain not only survives, but thrives. As it does it begins to control Cory, making him into a slave. Donovan's brain wants to continue to use his business empire for world domination, and will kill anyone who stands in his way. Cory's wife and colleague are helpless to stop what is going on. Now, there is a strong element of silliness throughout this thriller. The brain actually grows larger and pulses, and Ayers does the whole "must... stop....brain...before...it's...too...late' routine which quite possibly taught William Shatner a thing or two. But if enter into the spirit of the thing, this is one hell of an entertaining b-grade science fiction yarn, and lots of fun. For a different approach to the same Siodmak source material check out the early sixties mystery movie 'The Brain' starring Peter van Eyck.