Sunburn

Based on the novel The Bind by Stanley Ellin, this film tells the story of an insurance investigator (Charles Grodin) who goes to Mexico to look into the mysterious death of a wealthy businessman.  To deter any suspicions over his presence in Acapulco he hires Ellie, a beautiful model played by Farrah Fawcett, to pretend to be his wife.  Playing the role of a vacationing couple, they delve into the investigation, encountering many characters (including two played by Art Carney and Joan Collins) along the way.  Originally intended as a made-for-TV movie, Sunburn has more than enough twists and turns for the big screen.