Leda unexpectedly finds herself companion to her great aunt on a Mediterranean cruise. Assuming it will be a boring holiday with a crowd of elderly people, her horizons change as she explores the ports of call, and discovers that Aunt Ronnie is lively company. There's also a handsome ship's officer who seems to be attracted to Leda, plus intriguing fellow passenger Nick, who's hiding something. Added into the mix is a mystery on the ship - which becomes...