Hardened Vietnam War veteran Ross Archer returns home blinded in one eye from an injury suffered during frontline combat after escaping enemy imprisonment. Arriving at his house boat, Ross, now wearing an eye patch, is surprised to find a stranger living there instead of his wife Angela. Go-go dancer Kelly explains that Angela, who worked with her at Maxie Mark's club, offered her the boat to live in, having moved out months ago. Later, Ross learns from club owner and comedian Maxie Marks that Angela quit to look for better work after Ross was reported missing in action. Discovering Angela's current address from pin up photographer Carmen, Ross lets himself into her extravagant suite at the Ambassador Hotel and finds articles about millionaire Gregory Mann. When Angela returns carrying wig boxes, she shows Ross no affection and will not explain her current circumstances to him, despite a violent outburst from Ross. Returning to the house boat, Ross is forced to fight off an intruder, who escapes. When Kelly returns to the houseboat that evening, she coyly admits that she has reads his letters to Angela and is intrigued by him, prompting Ross to kiss her. The next morning, police Lt. Craig informs Ross that Angela jumped to her death at the hotel and left a suicide note, which Ross confirms is in her handwriting. Suspicious about the death, Ross insists on an autopsy and tells Craig about the prowler and the articles on Mann. Although reluctant to spend time on a suicide, Craig agrees to accompany Ross to the Mann estate, where they are greeted by the vacuous, etiquette-obsessed Mrs. Mann and the gentlemanly, wheelchair-bound Mann, who claims to know nothing about Angela. After they leave, Mrs. Mann questions her husband about a recent letter from South America, but he viciously insists that she is delusional. Locating shop where Angela purchased wigs, Ross learns that Angela bought a brunette wig and made a call from the shop to plan to meet someone at room 25 in the La Paloma hotel. When Ross arrives at the address, he finds an abortionist, who admits under pressure that a woman, who remained nameless, came to see him and died during the late-term abortion. When the spineless man attempts to return the $600 to Ross to assuage his anger, Ross attacks him, sending the man fleeing into the street where he is killed by a passing car. When Craig arrives at the scene, he reveals that the autopsy report showed Angela was dead before she was thrown from the roof. Although Craig assumes that she died from the abortion, Ross is still uncertain and goes to the club to confront Maxie, whom he has learned was having an affair with Angela, but learns nothing. Carmen calls Ross there, but before he can get to her studio, a knife wielding thug threatens Carmen for information about Judith Hagen, and kills her. Minutes later, Ross discovers Carmen's body and the very much alive Angela, disguised in a brunette wig. His wife explains that a woman looking similar to her, South American Judith Hagen, was blackmailing Mann with information that is now in a safety deposit box, for which Angela has the key. Carmen had taken Judith for the abortion, but when she died, Angela agreed to assist, making the suicide look like Angela had died, in trade for $25,000 of the blackmail money, which she planned on using to escape Maxie's possessive grasp. She knows Carmen's murderer was looking for the key. Ross and Angela then reminisce fondly about their reckless youth and early marriage and consider reuniting. The next day, while Angela, posing as Hagen, enters the bank to retrieve the contents of the safety deposit box, Ross spots the suspicious-looking Guy waiting outside. After they discover the package contains proof that Mann was actually war criminal Wilhelm Hauser, a major in the SS army, Ross insists that Angela return to her apartment, while he takes the package, luring Guy into a car chase. After driving off road and stopping his car, Ross engages Guy in a fistfight. Guy prevails, grabs the package and attempts to run over him, but Ross shoots Guy, causing the car and the evidence to explode in flames. Ross then goes to Mann's house, where he insinuates that he now is in possession of the proof after killing Guy. Mann divulges that after serving the SS military, he fled to Paraguay where he had a daughter, Judith Hagen, whom he abandoned when returning to the United States. He had ignored her recent attempts to contact him rather than face trial. Mann offers Ross $100,000 to keep quiet about his real identity and orders his wife to get the money from the safe. Appalled to learn of her husband's real identity, Mrs. Mann gets the money and adds an extra pill to his regular medications, causing instant heart failure resulting in Mann's death. She admits the murder to Ross, who takes the money and leaves. Hoping to reunite with Angela at the Ambassador, Ross instead discovers that Angela has fallen to her death from the apartment. He then goes to the club, where Maxie, in his drunken comedic rehearsal, admits to pushing Angela out the window when he found her in the apartment. Ross chases Maxie onto the beach, where he almost drowns him, but flashbacks of drowning an innocent woman during the war prevent him from continuing his killing. At Ross' boat later, Craig informs him that Mrs. Mann, due to inherit millions, deliriously repeated the amount of "$100,000" to police as she was taken away to a mental facility. Craig then hints that Ross is "due for some," and leaves him in peace, while Ross tells Kelly that his only plans for the future are to go fishing for a while and takes his boat into the ocean.