Intrepid detective. Schoolgirl. Everyone's favourite girl detective is back, with all her trademark off-the-wall humour, action and friendship. This time, though, it's an adventure on the wide open ocean, and Ruby is all at sea... Can she crack the case of the Twinford pirates while evading the clutches of a vile sea monster as well as the evil Count von Viscount? Well, you wouldn't want to bet against her...