This is one book from the Dark is Rising series by Susan Cooper. One of my all time favourite series which I still turn to once a year to re-read even as an adult. And by the way the books are in no way similar to Harry Potter(and written years before HP)This absolute disaster of a movie has absolutely no bearing on the books. Avoid it at all costs. Read the books or even listen to the unabridged audio books which are done extremely well.