Miss Marple navigates treacherous waters to catch a maritime killer! One of Britannia's ships is manned by a crew of delinquents trying to build new lives. But it's their old lives that figure into this cunning mystery: Someone aboard ship wants to hone the ruffians' natural bent for crime by turning them into expert thieves. And that someone will kill to keep the plot secret.

Margaret Rutherford steers her third course as spinster sleuth Miss Marple, sailing full speed into mystery and mayhem on the high seas. And it isn't just her rapier-sharp mind that gets a workout. When her demise seems imminent, Miss Marple proves why she was Ladies' National Fencing Champion in 1931!

Actors: Margaret Rutherford, Lionel Jeffries, Charles Tingwell, William Mervyn, Joan Benham, Stringer Davis, Nicholas Parsons, Miles Malleson, Henry Oscar, Derek Nimmo, Gerald Cross, Norma Foster, Terence Edmond, Francis Matthews, Lucy Griffiths, Bernard Adams, Tony Quinn, Edna Petrie,

Directors: George Pollock,

Writers: David Pursall, Jack Seddon,

Genres: Comedy, Mystery, Thriller,

Format: MOD - SD,