Leepike Ridge

Eleven-year-old Thomas Hammond is in for the ride of his life when he's swept downstream and underground aboard a crumbling raft of Styrofoam. Washing up on a dark subterranean "beach," his only companions are an impulsive dog named Argus and a corpse, from which he takes a flashlight and an all-too-limited supply of batteries. What Tom finds under Leepike Ridge—a castaway, four graves, a tomb, and buried treasure—will answer questions he hadn't known to ask and change his life forever. Now, if he can only find his way home again. . . .

An original mix of Robinson Crusoe, King Solomon's Mines, The Adventures of Tom Sawyer, and The Odyssey, N. D. Wilson's first book for young readers is a remarkable adventure, a journey though the dark of the grave and back out into the light.
From the Hardcover edition.