Alfred is described as a "squarely built man of middle age with a gentle face and mild brown eyes". His voice is "quiet and precise with a very clear enunciation". His head is sunk into his shoulders, and he gives "a curious impression of inertia".
At the beginning of the novel, Lydia tells Alfred that although Simeon is generous with money, he expects them to behave like slaves. She tells Alfred that he should stand up to his father. Alfred says that his father has done everything for them. He is distressed when Lydia says that she does not like his father.
According to Lydia, Alfred is usually a gentle soul, and hardly ever says an unkind thing to anyone. She sometimes gets annoyed with him because he is not sufficiently suspicious, and seems to have no consciousness of the evil in the world.
Simeon's original plan for Alfred was for him to go into a cavalry regiment in the army. However, after Simeon's other sons, Harry and David, refused to go into the family business as he had planned, Simeon made Alfred come back and run the business. According to David, Alfred minded this very much at first, but he had always been under his father's thumb.
Alfred does not get along with his brother Harry, and they did not get along even as children. According to Simeon, Harry used to jeer at Alfred, calling him "old Slow and Sure".
Alfred is known for his devotion to his father. However, Simeon describes this as boring, and say that Alfred looks at him with "dog's eyes", ready to do anything he asks.
When Simeon tells Alfred that Harry will be living at Gorston Hall with them, Alfred becomes upset, mentioning the disgraceful way Harry had behaved, after all Simeon had done for him, and saying that he resents Harry for his father's sake.
Alfred is in the dining room with Harry, when the noise of furniture being overturned, and a scream, is heard from Simeon's room upstairs. When Simeon is found dead, Alfred is the only member of the family to step near the body, and look down at his father.
Alfred is dazed and shocked by his father's death, so much so that his eyes are "like those of a suffering dog".
When Alfred realises who Poirot is, he tells Poirot that he must find out the truth, and that his father must be avenged. He says that he will take responsibility for any expense. Alfred then becomes upset, saying again that his father must be avenged, and Lydia calms him down.
Alfred later invites Poirot to stay at the house, saying that he must do his utmost to solve the case.
After Simeon's will is read, the family discuss whether Pilar Estravados should have her mother Jennifer's share of the estate. Alfred is asked to speak first, because he is the eldest. He says that Pilar should be allowed to stay at Gorston Hall and given an allowance, but she has no legal claim on the inheritance, as she is not a Lee, and is a Spanish subject. However, after Lydia gives her opinion that Pilar has no legal claim but has a moral claim on the inheritance, Alfred admits that he was wrong, and says that Pilar should have her mother's share of the inheritance. He later takes Pilar into his study to explain to her what the family has decided.
During the denouement, Poirot explains that he considered Alfred a possible criminal from a psychological standpoint. He says that Alfred had controlled and subordinated himself to the will of his father for many years, and in such circumstances, it was always possible for something to snap. He also suggested that it was possible that Alfred could have held a secret grudge against his father, which grew in force, while never being expressed in any way.
At the end of the novel, Alfred and Lydia decide to sell Gorston Hall. Alfred offers David some of the things that had belonged to their mother, but David refuses them. Harry reveals that he was not serious about wanting to live at home, and apologises for riling Alfred up. Alfred says that he has to learn to take a joke.
Alfred tells Lydia that he will be glad to leave Gorston Hall, as there are many interesting things that they could do together, and to live on there would be to constantly be reminded of the nightmare of his father's murder.