A scientist takes the brain of dead man and revives it via electrodes as it lays suspended in a tank of liquid. Soon, the brain grows to possess enormous psychic powers and inflicts its personality upon the doctor who saved it, creating a "Jekyll and Hyde" paradigm.
When their hospital ship sinks in the South Pacific during World War II, military nurse Elizabeth Smythe (Linda Darnell) and Marine Michael Dugan (Tab Hunter) find themselves stranded — and soon enough, falling in love — on an idyllic tropical island. But when British pilot William Peck (Donald Gray) crash-lands on their cozy little atoll, Dugan suddenly discovers he has a rival in love.