Fairy Tale - Stephen King - First US Edition

Charlie Reade looks like a regular high school kid, great at baseball and football, a decent student.

But when Charlie is seventeen, he meets a dog named Radar and her aging master, Howard Bowditch, a recluse in a big house at the top of a big hill, with a locked shed in the backyard. When Bowditch dies, he leaves Charlie a cassette tape telling a story no one would believe - inside the shed is a portal to another world.