This final entry in Margaret Rutherford's Miss Marple casebook is the only one not based on an Agatha Christie story. While David Pursall and Jack Seddon's original screenplay has all the basic characteristics of a Christie whodunnit, there are too many offbeat characters, a glut of inconsequential chat and more comedy (mostly for the benefit of an overcooked Lionel Jeffries) than you'd find in the great Dame's marvellous mysteries. Having said that, it's neatly staged and the solution is neither blatantly obvious nor buried under a mass of barely perceptible clues.

During an annual board of trustees meeting, one of the trustees dies. Miss Marple thinks he’s been poisoned after finding a chemical on him. She sets off to investigate at the ship where he had just come from. The fourth and final film from the Miss Marple series starring Margaret Rutherford as the quirky amateur detective.