Mr Denman (The Thumb Mark of St. Peter)

In the short story The Thumb Mark of St. Peter, Mr Denman is the father of Geoffrey Denman. He lives with his son and his daughter-in-law at Myrtle Dene. Mr Denham has been exhibiting signs of insane behaviour (there is madness in the family) and in the course of the story, Geoffrey Denman had been planning to put him into an asylum. Mabel Denman apparently stood up for her father-in-law but Geoffrey was adamant. Like many old people, Mr Denman has also been prescribed atropine eye drops for his eyes.