Lewis gets to fulfill a dream of living in a mansion when he goes to stay with his eccentric Uncle Jonathan in his three-story stone home. Before school starts he spends his time exploring unused rooms and secret passageways- which is almost as much fun as playing poker with their next door neighbor or watching his uncle's magic tricks. Things take a turn for the worse when Lewis discovers a different kind of magic lurking in the walls of the old mansion- one that ticks quietly behind every wall like a human heartbeat.