Billy and his friends know that Waterfall Woods is out of bounds; strange things are rumoured to have happened there, and no one in their village has ventured past its walls for decades... But when they discover a secret way in, Billy and his best friends, Anna, Jimmy and Andy, can't resist the temptation to explore! Only to quickly discover that the woods are brimming with magic and inhabited by all sorts of unusual creatures, including a whole community of sprites who need the children's help! With magical battles, a long-lost mythical city, fantastical flying machines, epic feasts and one GIANT rescue, get ready for an adventure you'll never forget!