Set aboard a luxury cruise liner touring Mediterranean holiday hotspots, it follows the ship's new cabaret singer, Jack Grayling, who discovers there are sinister elements below the surface. After a passenger is found murdered in the first port of call, ambitious First Officer Kate Woods' dream of her own command is thrown into jeopardy and Jack finds himself thrust back into his former life as a detective. A wave of murder mysteries follows - each set against the backdrop of a different stunning coastal destination.