In the short story The Case of the Caretaker, Harry Laxton is the son of Major Laxton. He appeared as a character in a manuscript written by Dr Haydock. He is described as being "tall and broad-shouldered".
In his youth, Harry had been a rascal, but he had also been very charming, and everyone had always felt indulgent to him. He got entangled with Bella, the tobacconists' daughter. After this relationship had been ended, Harry was sent to Africa. When he returned, he was married to a wealthy girl.
Harry had lived in the dower house at Kingsdean House as a child, and had always been fascinated by the old house. Upon his return to St. Mary Mead, he purchases Kingsdean House as a home for himself and his wife, Louise. He pensions Mrs Murgatroyd off, and finds her a cottage to live in.
As Harry drives into the gates of Kingsdean House, he has to swerve to avoid hitting Mrs Murgatroyd, who springs up in the middle of the road. He tells Louise that Mrs Murgatroyd has gone "a bit queer" after the death of her husband, and resents the old house being pulled down. Mrs Murgatroyd shakes her fist and shouts after them.
Louise is distressed by Mrs Murgatroyd's behaviour, but Harry feels that reporting it to the police will only increase sympathy for Mrs Murgatroyd, and that she will eventually get tired to cursing them.
Harry later arranges for Mrs Murgatroyd to go to America to join her son, and offers to pay for her passage.
When Louise is injured in a riding accident, one of the witnesses runs to the house to get Harry.
Miss Marple surmises that Harry married Louise for her money, since she was of a different type from the women he was known to admire. She suggests that Harry murdered Louise to get the money, and wanted to marry Clarice Vane.
Miss Marple observes that Harry is the sort of person who would lay plans carefully and leave nothing to chance. She suggests that he let Bella Edge think that he was still attached to her, in order to manipulate her into getting a drug with which he could kill Louise after the accident, before the doctor arrived.
Dr Haydock reveals that he was saying some consolatory words to Harry after Louise's death, when Harry flung himself down on the settee, and a hypodermic syringe fell out of his pocket. An autopsy found strophanthin in Louise's body, and strophanthin was found in Harry's possession.
It is also revealed that Harry had paid Mrs Murgatroyd to pretend to curse him and Louise.