The Lost Boy by Greg Ruth

Some mysteries are too dangerous to leave alone . . .After Nate moves into his new house, he discovers an old tape recorder in his bedroom and is suddenly thrust into a dark mystery about a boy who went missing many years ago. Now, as strange creatures begin to stalk Nate, he must partner with Tabitha, a local sleuth, to find out what they want with him. But time is running out, because a powerful force is gathering strength in the woods at the edge of town, and before long Nate and Tabitha will have to confront a terrifying foe and uncover the truth about the Lost Boy.