Harry Elser (Elisha Cook Jr.) is a mentally disturbed man who plots an assassination of a candidate for Mayor, Walker Wylie (Conrad Nagel). Under the guise of being a maintenance man, Harry gets into Walker's office. Harry was placing a bomb in Walker's desk, but he is busted, but gets away before he can be stopped. He hides in a closet, and when the coast is clear, he gets on a crowded elevator and puts the bomb in a woman, Jane Kimball's (Whitney Blake) purse. Harry is hit by a truck, but he tells the police about the bomb before he dies. The police race against the clock to get it, before it goes off at 11pm.