The black widow spider mates to kill--and so does the femme fatale of this noir thriller. Catharine (Theresa Russell) makes quite a glamorous living by marrying well and then carefully murdering her devoted husbands after ensuring that her name's on the will. No one suspects that the beautiful and affluent widow is actually a killer, as she hides her tracks well, using undetectable poisons. But her luck turns when federal agent Alexandra Barnes (Debra Winger) takes a closer look into the case and suspects she's found a serial killer. Soon Barnes books a flight to Hawaii, where Catharine's doing her mourning in the sun, and discovers that the widow has already gotten her claws into a highly successful hotel tycoon. However, Barnes quickly becomes obsessed with both her alluring subject and with the sophisticated businessman--a situation Catharine is sure to exploit.