PI Mike Hammer is out for a late-night walk in the rain when he sees a woman being pursued across a bridge. He deals with the man, but, terrified, the woman jumps to her death.
Pat Chambers, Hammer’s police department friend, identifies the pair as Communists. Hammer visits a meeting of the local party and is mistaken for a Soviet spy. Into the mix comes Oscar, the insane brother of a political candidate on an anti-corruption ticket, who Hammer must deal with so that the politician’s career prospects aren’t spiked. But is Oscar really what they say he is?
Meanwhile, Velda, Hammer’s adored secretary, goes missing, and Hammer soon finds out that the two incidents are linked by a deadly thread . . .