The series based on Agatha Christie's novels about an amateur sleuth returns, with Julia McKenzie taking on the lead role of Miss Marple. When business magnate Rex Fortescue, his young wife and their maid are found murdered, Miss Marple notices that the circumstances recall the nursery rhyme Sing a Song of Sixpence. It is not long before she discovers that secrets and scandal run deep in the Fortescue family, but the significance of the song itself is harder to unravel