 In Long Beach a local bar-girl, Dolores Chapman, has been murdered and the investigation centers around the crew of the submarine USS Moray. Cmdr. James Page, captain of the Moray, is involved in testing new equipment from Alpha Electronics. He meets with Alpha spokesmen Gordon Russell and Lou Hansford to set up the test, and finds that his father-in-law, Anthony Beldon, has bought into the company. Beldon consults Perry Mason about suing the U. S. Navy and relieving Page of his command, which Perry declines. Cmdr. Page is found stabbed to death with a special screwdriver. Robert Chapman, Delores  husband and member of the Moray s crew, becomes a prime suspect in both murders. Perry is retained anonymously to defend Chapman.