While her milliner mother Rosamund is abroad in Paris twelve-year-old Vinnie Fyfe is left behind in Brighton. She finds comfort in her eccentric Aunt Bets her new friend Temitayo and the Brighton Aquarium - where the arrival of a giant octopus will change her life forever. At first terrified then fascinated Vinnie begins to produce drawings of the incredible creature and is sure that a bond is developing between them. But meanwhile there is a dark and dangerous mystery afoot - involving Rosamund's real reasons for disappearing so suddenly and the ominous behaviour of her former employee Mr Jedders . . .