Abandoned by James, Agatha hops on a plane to the South Pacific. There she meets a honeymooning couple but tragically, the new bride accidentally drowns. Returning home to Carsely, Agatha finds herself involved in a strangely similar situation - a woman, dressed in a wedding gown, is found floating in a river. The police believe it is suicide but Agatha, spurred on by memories of her disastrous marriage, sets out to prove them wrong.