Murder Ahoy!

Lighthearted film in which the genial, elderly sleuth Miss Marple investigates when the wealthy trustee of a charity is murdered by means of a poison added to his snuff. The charity's work involves rehabilitating young delinquents by sending them to sea - and it is on board a seagoing vessel that Miss Marple must pursue her quarry. Margaret Rutherford's final outing as Agatha Christie's famous detective.