Have Book - Will Travel

Max and Darla are unlikely friends: he is an upper class city boy, and she a village girl who works in a laundry. When Max spends the summer with his uncle, they meet secretly to read from an old book that Darla has found in a dusty warehouse.The old book turns out to be a portal that takes Darla and Max on a series of breathtaking adventures, and sometimes gets them into big trouble. In the haste of escaping mortal danger, Darla and Max end up in an alternative world. When Max is trapped in another boy's body and Darla doesn't know what he looks like, how can the two friends be reunited and find their way home?