Unfaithfully Yours (1984 Film) - Plot

Plot

Claude Eastman (Dudley Moore) is a composer and the conductor of a prestigious symphony who has recently married beautiful Daniella (Nastassja Kinski), a much younger woman. While travelling, he sends a message to his friend Norman Robbins (Albert Brooks) to keep an eye on his wife, but the message is garbled by Claude's Italian valet Giuseppe (Richard Libertini), and instead of looking after Daniella, Norman hires a private detective named Keller (Richard B. Shull) to investigate her.

The private eye's report, which comes with a fuzzy video, is that Daniella had an assignation with a man who, by wearing Argyle socks, appears to be Maxmillian Stein (Armand Assante), a handsome violinist with the orchestra – and Claude's protégé – who is well known as a ladies man.

Claude at first doesn't directly confront Max. When Max eventually meets Daniella, it is at a restaurant where Claude, overwhelmed with jealousy, duels Max with violins by playing a Csárdás, the famous composition of Vittorio Monti.

Claude confronts Daniella, who feels guilty because she is keeping a secret from her husband, only not the one he thinks it is. When she tells him that it's no big deal, Claude is enraged. As he conducts Tchaikovsky's "Violin Concerto", an elaborate plan to kill Daniella and frame Max for the murder runs through his mind, but afterwards, when he tries to carry out his plan, unforeseen circumstances intervene.