The Red House Mystery is a novel by A. A. Milne about the mysterious death of Robert Ablett inside the house of his brother, Mark Ablett while there was a party taking place. It's a whodunit novel with a simple story that's skilfully told. The novel is set during a house party in the mansion home of Mark Ablett known as the "red house." Mark had many guests in the party including a widow and his daughter, an actress and a young man named Bill. While the party was going on, Mark's long-lost brother Robert arrived in the house and shortly after was found dead. Then suddenly the guests noticed that Mark had disappeared. Anthony Gillingham, a very interesting man who just went to the house to call on his friend Bill acted as the "investigator" to the crime.