Dale and Laura Corey are a happily married couple who own an electronics store; he does a lot of electronic eavesdropping for clients, she was a cop on the force with Cannon a few years back, and hires him because Dale is being threatened after bugging some hotel rooms for the owner and catching three guests in compromising positions. The three are being blackmailed, and think Dale is behind it. Cannon interviews them and determines that one of the three is blackmailing the other two.

A cop feels guilty over a man he injured.

A blackmailer's murder brings his Swiss wife to America, and Cannon discovers still more dealings.