[1][2] When 21-year-old Melissa Collins (Eileen Elton) commits suicide, her guardian, the domineering American newspaper publisher William T. Marshall (Dennis O'Keefe), searches (in flashback) for a reason.

In this, she asks Marshall to take revenge on her lover, philandering musician Larry Shaw (Vernon Greeves), who caused her such pain he made life not worth living.

Marshall hires criminal mastermind, Karnak (Anton Diffring), an avid philatelist.

Meanwhile, Marshall's loyal secretary, Katie Whiteside (Ann Sears), attempts to calm her boss's obsessive desires for vengeance.

Dennis Schwartz writing in Ozus' World Movie Reviews, called the film a "tedious noir crime drama about the insanity of revenge";[3] Leonard Maltin also described the film as "tedious";[4] and TV Guide noted, "the plot is very confusing, making it hard to follow this picture.