The Queen's Jewels (Murder, She Wrote, Book 34)

Jessica Fletcher has always wanted to take a transatlantic voyage on the legendary Queen Mary 2. Now, she's finally getting her chance. But when the investigation of a stolen diamond follows her up the gangplank, she must try to enjoy the sumptuous seaborne surroundings while searching for a priceless diamond-and the person desperate enough to take a life for it.