Peter Duluth, again, returning from Mexico to Iris but still susceptible, pursues the death of defenseless Deborah Brand who had appealed to him. He is almost submerged by the seductive attentions of Russian Vera, and is unable to save the life of tourist Mrs. Snood who carried information from the dead girl. In a succession of doubletakes and doublecrosses, Peter confides in the wrong people, but is finally able