Novel
A tie-in novel was published alongside the movie's release in 1993, written by Todd Strasser. The novel elaborates on the movie, detailing how Henry was born a sociopath, rather than being some personification of evil. In the novel, Henry's mother Susan eventually discovers that Henry is unable to understand emotions like love and sorrow, and that deriving pleasure from selfish actions and the torment of others is one of the only things he truly feels. The book also concludes differently from the movie, ending with Mark returning to Uncle Wallace's home in Maine one year later. Mark and Susan visit Henry's grave, which includes an epitaph: "Without Darkness There Can be No Light".
Read more about this topic: The Good Son (film)