While enjoying a leisurely ocean cruise in the company of secretary Della Street, Perry Mason is approached by passenger who is worried about the wellbeing of her husband. Not long afterward, her husband is seen jumping off the ship, an apparent suicide—but when the body is recovered, it turns out that he was shot. Accused of murder, the wife puts her fate in the hands of Perry, who in the course of piecing things together unearths the fact that the husband had once accepted a huge bribe while serving on a jury. The case takes many shocking twists and turns before revealing its surprising conclusion.