In this very funny and irresistibly silly junior fiction book, The Bad Guys meet The Treehouse series, but in a brilliantly invented submarine.

Welcome to Monkey Island!

Poppy and Billy live in a lighthouse with a gorilla named Harold and the world’s greatest inventor – their mum! But a normal day is turned upside-down when Mum is kidnapped by The Fugitives and taken back to their secret volcano lair.

Luckily, Poppy and Billy have Mum’s greatest invention yet: a marvellous submarine.

With the help of the animal crew, the twins set off on a wild adventure to save Mum, and maybe even stop The Fugitives from draining the Pacific Ocean.

There’ll be pirates, blue whales, exploding basketballs, and a whole lot of water.

Just as well Poppy and Billy aren’t regular kids…