When Finn is sent to live with his great-aunt for the summer, he's thrilled by the possibility of adventure offered by the wilderness surrounding the house. But when he stumbles across an old shack inhabited by a glowing green ghost and his specter of a dog, things quickly take a turn for the weird. The ghost, Jack Henry, has a special connection with the land and its creatures. He rescues an orphaned wallaby and helps Finn learn to understand the cry of the kookaburra. When a greedy businessman wants to bulldoze the trees in order to mine for gold, Finn and Jack combine their practical and spooky powers to save the land and the animals that live there. Themes of environmentalism and altruism make this chapter book much more than just a ghost story.