Wealthy scion Peter DeHaven, about to marry socialite Christine Lunceford, wakes up after bachelor party revelry to find he's been turned invisible by eccentric college professor Reginald Shotesbury. An unbelievable series of events is revealed by several witnesses testifying in a "mystery trial" to determine the reason for DeHaven's "disappearance".

The last movie with Jerry Lewis and Dean Martin together, is a satire of the life in Hollywood. Steve Wiley is a deceiver who cheats Malcolm Smith when he wins a car, claiming that he won it too. Trying to steal the car, Steve tells Malcolm that he lives in Hollywood, next to Anita Ekberg's. When Malcom hears that, they both set out for Hollywood and the adventure begins...