Death on The Nile by Agatha Christie.
Simon Doyle, leaving his fiancé Jacqueline de Bellefort to marry an old school friend of Jacqueline, rich American Linnet Ridgeway. Three month later the couple meets the abandonee, longing for revenge, on their honeymoon, a cruise on the Nile. One evening the situation escalates. Jacqueline pulls a pistole and shoots Simon into his leg. The next morning Linnet Doyle is found shot dead in her bed.
