Losing his job, Lou is taken by Bud to answer a newspaper ad to assist in an experiment by Dr. Bluzak (Byron Foulger). The doctor says 97 percent of all accidents happen to three percent of the human race- those referred to as accident prone. His theory is that it is the product of a subconscious fear and offers Lou $100 plus expenses for electrified therapy, after which no harm will come to him for 24 hours. As Lou avoids accidents and being punched, he begins to believe he is indeed invincible. Lou runs into a gunfight between a bank robber (Benny Burt) and police to subdue the criminal. At the apartment house, Lou has a run-in with a continual foe, Prof. Roberto (Fortunio Bonanova). He is always boasting of his fencing prowess and Bud encourages Lou to challenge him to a duel while no harm can come of him. The tone changes when they discover Dr. Bluzak has been locked up in a lunatic asylum and accidents return. Lou must face the duel, however.