Ben Sillman, an East Coast hitman nicknamed the Animal, pulls off an escape from a federal courthouse, where he is being tried for income tax evasion. He shoots two federal marshals. Erskine and Daniels head up the FBI's manhunt, working with Tom Colby, Erskine's former partner who now agent in charge of the bureau's west coast office. Sillman is on the outs with the East Coast mob and tries to force a West Coast mobster to help him flee the country. Complicating the FBI's search is the fact Sillman has kidnapped a woman for possible leverage.