After a trying day of doing favors for friends and an encounter with a blood-bank doctor, an under-the-weather Fonzie falls asleep on the Cunningham's couch while watching a horror movie and feverishly dreams that a mad scientist is after what makes him the Fonz...his cool!

Dressed as a bride and groom at the Jefferson High masquerade party held aboard a boat cruising Lake Michigan, Jennie Piccolo and Fonzie both say "I Do" in a wedding skit performed by their drunk host, Captain Singer, unaware that a ceremony performed at sea by a bona fide ship's captain may be the real deal.