Meet Lottie. She's a little girl just like you - she loves adventures, mysteries and her little puppy, Biscuit. When Lottie finds an old book all about beasts of the world in her attic, she can tell it's going to be the start of a brilliant adventure! All she needs is a beast of her own to track . . . and she doesn't have to wait long. There are strange rustlings and footprints in the Branksea Island woods! Lottie and her friends Mia and Finn set themselves the task of tracking down the Beast of Branksea. But what exactly is this mysterious creature? And can the trio find it before Mia's older brother Sammi ruins the whole adventure?