After passing out at his bachelor party, Peter (Jeffrey Lynn) is moved to the college dissecting table by his friends as a joke. But the prank turns serious when Professor Shotsbury (Edward Everett Horton) injects the young man with a serum that renders him invisible. This turn of events complicates Peter's impending marriage to Christine (Marguerite Chapman). But, as Shotsbury and his daughter Joan (Jane Wyman) work on an antidote, Peter explores some of the advantages of being unseen.