Twelve-year-old Charlotte is on a cruise. She meets a nice lady who suddenly disappears, but everyone wants to make her believe that the woman was never on the ship. With the help of her new friend, Jack, Charlotte must solve the mystery. This intriguing adventure is written in simple language, comprehensible to students with a basic knowledge of English. The book includes a selection of grammar and vocabulary exercises, a dossier about British explorations and pirates and files Mp3 with the complete recording of the text.