An interactive choose-your-own-adventure style puzzle book follow-up to Lost In the Museum. Help William the hippo and his friends solve the puzzles and save the exhibition! William the hippo and his friends live on 5th Avenue, New York, inside the Metropolitan Museum of Art. At night, when the museum is closed and all the visitors have gone home, their adventures begin. An exhibition of mythical creatures is due to open, and it’s all the animals in the museum can talk about. The amazing exhibits have been sent from all over the world. They are packed very carefully and, to keep them safe, each box has a puzzle lock that needs to be solved before it will open. But it’s the night before the opening, and the curators still haven’t managed to figure out the puzzles! William the hippo is the wisest creature in the museum. Can you help William and his friends travel the museum, collect the clues, solve the puzzles, and save the opening?