After a break from their trips in the tree house, Jack and Annie are delighted to find that it's back! Morgan le Fay needs their help, but they'll have to become Master Librarians first, and that means solving four riddles. For the first one, Morgan sends them deep into the middle of the ocean. Jack and Annie ride in a mini-sub and meet jellyfish, sea horses and an octopus. But there are some scary sharks in the deep and the friendly dolphins have to come to the rescue. . .
| ISBN: | 9781862305731 |
| Publication date: | 1st January 2009 |
| Author: | Mary Pope Osborne, Philippe Masson |
| Publisher: | Red Fox an imprint of Penguin Random House Children's UK |
| Format: | Paperback |
| Pagination: | 68 pages |
| Series: | Magic Tree House |