Luke is a lonely child caught in the middle of a divorce and living with his mother, Claire, when he meets Daniel on a playground. The two immediately bond, and Claire seems glad Luke has found a friend to keep him occupied. But Daniel isn't like other boys, and he gradually becomes aware of the power he has over Luke. As the two grow up together, Luke at times shuts Daniel out of his life, although he can't quite seem to cut the ties completely -- either through his own reluctance or from Daniel's influence. Meanwhile, Daniel bides his time and grows stronger as Luke continues to give up bits and pieces of himself, until the two are virtually one person.

This is an absolutely riveting and chilling story about some deeply dysfunctional relationships: not only Luke and Daniel's, but Luke and Claire's as well. Although some readers may guess Daniel's secret early on, personally I found myself guessing until the very end. But the story is not as much about who Daniel is as what he does in this twisted friendship with Luke. They battle for control, power and ultimately life and death -- a struggle complicated and sometimes mirrored by Claire's increasingly bizarre behavior. This isn't an easy read, but it's grimly fascinating and kept me on the edge of my seat, haunting me long after I had finished the last page.