In the novel Crooked House, Charles Hayward is a young man serving in the diplomatic service and is the chief protagonist and first person narrator of the story.
During the closing years of the Second World War, Charles had served in Cairo and there he met and fell in love with Sophia Leonides, at that time also working for the foreign service. Charles was subsequently posted somewhere in the Far East. Coming back to England two years later, he asked Sophia to marry him. However Sophia tells him that her grandfather, the wealthy Aristide Leonides had just died under suspicious circumstances and until the truth is found, they cannot marry because a cloud of suspicion would always hang over her and the rest of her family. Moreover Sophia does not want to tell him her views on the death. She wants how to see the family from an unbiased outside perspective.
Charles approaches his father, Arthur Hayward for help. He s not only an assistant commissioner of Scotland Yard but is also supervising the case. "The Old Man" Hayward uses Charles' relationship with Sophia to advantage and takes the opportunity to insert Charles as a house guest of the Leonides family at Three Gables. Charles dislikes being a police spy on his girlfriend's family but his father reasons that the only way to solve the case is to get the "inside dope" on the family. Sophia agrees and thinks this is just about the only approach that would help. Charles is well-placed. Besides the help of Sophia, he has some standing with the police as he had worked with Special Branch during the early days of the war. In addition he knew Chief Inspector Taverner, the investigating officer, well.
After the murder is resolved Charles once again proposes to Sophia and tells her that he is being appointed to a post in Persia. He wishes her to join him.