Adding and Subtracting Book

I watched this movie many times I think on lifetime or a channel similar and absolutely love it and I was at a book sale the library was holding and came across this jewel and knew immediately I had to read it because I didn't know there was a book. Turns out this isn't a book turned into a movie, it's a movie turned into a book and I even did research to make sure. The movie is written by the talented Ian McEwan.

The Good Son is about a boy named Mark who lives with his aunt and uncle for a couple weeks after his mom does and his dad goes to Japan to save his business. Mark has two cousins, Henry and Connie and Henry is basically the devil inside a child's body and all these events happen and basically the kid has no remorse for anything he does.
I give this book 5 out of 5 Macaulay Culkins because the movie is the best.