Murder Ahoy!, 1964...
Unlike the previous three films that were adapted from Christie novels – The 4.50 from Paddington (Murder, She Said – the only Miss Marple novel used), After the Funeral (a Poirot mystery, adapted for Miss Marple with the title Murder at the Gallop) and Mrs. McGinty's Dead (another Poirot novel, adapted as Murder Most Foul) – this film used an original screenplay that was not based on any of Christie's stories.