When Charlie's longed-for brother is born with a serious heart condition, Charlie's world is turned upside down. Upset and afraid, Charlie flees the hospital and makes for the ancient forest on the edge of town. There Charlie finds a boy floating face-down in the stream, injured, but alive. But when Charlie sets off back to the hospital to fetch help, it seems the forest has changed. It's become a place as strange and wild as the boy dressed in deerskins. For Charlie has unwittingly fled into the Stone Age, with no way to help the boy or return to the present day. Or is there?