If you read one Octonauts book, read this one - the point is more clear and more valuable (but it's still just plain cute). ( )

In this Octonaut adventure, the intrepid crew are heading for a vacation, but find another adventure awaiting them instead. The Great Reef City does not live up to its reputation; the inhabitants are all missing, and the city is bleached white. Captain Barnacles takes the team out to explore, but as they search for clues in the city, ghostly noises surround them. The illustrations show cute, translucent creatures floating around them, just out of sight. Eventually, they find the last resident of Great Reef City, an old turtle named Mr. Slowstache. He tells them that when he first moved to the city, it was a vibrant and colorful place, but as more animals moved in and more buildings went up, the coral beneath the city began to turn white and brittle. Eventually, everyone returned to their old homes and left Great Reef City abandoned.

The Octonauts offer to help Mr. Slowstache move his possession to a new home. They search several promising locations, such as sandy dunes at the beach, a mangrove forest, and seagrass meadows. Sadly, Mr. Slowstache isn't satisfied with any of his options. He realizes that his reef was a truly special place. If they can't find him a new home, the Octonauts will just need to fix the one he wants. Lucky for them, Shellington has solved the mystery. The coral is alive, and all the buildings and pollution are killing it. And the ghosts aren't ghosts at all, but algae that are starving without their coral, and thus look pale and spooky.

The gang work on cleaning up the Great Reef City, and with the help of other sea creatures the job is soon done. In a short time, the coral is bursting with color and beauty, the city has reverted to its natural look without all the buildings and streets, and everyone is happy. The story blends the whimsical and slightly absurd, as do previous Octonaut books I have read, but this one includes an educational component lacking from other books. It teaches children about the importance of caring for coral and the ocean environment. I love the art, which is quirky and adorable, and find the stories to be fun. To be honest, I prefer the fantastical adventure in Sea of Shade or The Only Lonely Monster over this more straightforward quest, but it's still an enjoyable read. This story will appeal to many young readers, beyond just the fans of the television show inspired by these books. ( )