Under the Ocean is one of four books in our Treasure Hunt Puzzles series. You’re visiting a deep-sea research centre, and get trapped inside a submarine that sinks below the ocean. This is a special kind of book. It contains a story with lots of puzzles that lead you on an adventure. Now you must take control and navigate a safe route past mines and sharks – all by solving sequence and volume puzzles, unravelling patterns, negotiating mazes and more. And, finally, use your answers to solve the ultimate puzzle and return to the research platform.