The author of the novel 'The Angry Hills' is Leon Uris, a four-letter word which is the answer to the crossword puzzle. Uris was an American novelist and author of many best-selling books, including 'EXODUS' and 'TRINITY'. He wrote 'The Angry Hills' in 1959, a novel set during World War II in Greece. The novel follows the story of an American journalist who is sent to Greece to cover the war and his experiences there.