MONSTER MISSION - Macmillan

We must kidnap some children,' announced Aunt Etta. 'Young, strong ones. It will be dangerous, but it must be done.' Three children are stolen and taken to a bizarre island, which is home to some extraordinary creatures - including mermaids, selkies and the legendary kraken. The island is the base for a very mysterious mission. But the magical adventure is cut short when the island is suddenly under siege. Can the children save themselves and their new friends?