This is going to sound like a stretch, but trust me on this one. Read "The Talisman" by Stephen King and Peter Straubb. It's a sort of "Huck Finn horror story." It's all about the (quite frightening) adventures of a kid named "Travelin' Jack." He has to go on a quest to save his mother. He journeys on two different planes of existence - an alternate and very dangerous universe and the real but often just as dangerous real universe.
Like I say, trust me on this one. If you like Huck and Tom, you will like Jack and "Wolf".