 At a beach-house poker game, Larry Benton accuses Mike Granger of cheating. They fight and Granger is killed with his own gun. Johnny Clay offers to dispose of the body. One of the poker players, Ben Wallace, tries to blackmail Larry, knowing that his brother is wealthy oilman Steve Benton. But the whole thing is a set-up because Granger is alive and in on the plot. Steve Benton confronts his brother with $20,000 of forged checks to Clay, then consults Perry Mason about the issue. Larry steals $20,000 from Clay to cover the forged checks, but Steve goes to return the money. He finds Clay dead and wipes off fingerprints. Discovered in the act by Wallace, Steve is charged with murder. Perry proves there is no honor among thieves in solving the case.