Nelson Hayward is running for senate as a man tough on crime. His campaign manager, Harry Stone, demands the candidate dump his mistress. He backs up the demand with threats to expose the politician's shady past. But Stone approves of Hayward's publicity-minded lie that anonymous killers are threatening the politician's life, little guessing that Hayward will murder him and blame it on these invented assailants. Hayward sets up a tricky alibi for himself that includes a surprise birthday party for his wife. No one guesses the truth except that annoying Italian cop in the rumpled raincoat - the redoubtable Lt. Columbo.