In the novel After the Funeral, Mortimer Abernethie was the son of Richard and Coralie Abernethie. Some six months before the events in the book, Mortimer had contracted infantile paralysis (polio) and had died after a short illness. Mortimer's death shocked Richard. His wife had already died some time ago. One more son had died in infancy. Mortimer's death left Richard with very little to live for.
Mortimer had been a particularly strong young man. He was a keen sporstman and a good athlete and was seldom sick throughout his life. Lanscombe, the butler, recalled that Mortimer was always going off to Norway for fishing, Scotland for shooting and to Switzerland for winter sports. Just before he contacted the illness, Mortimer had been about to become engaged to a very charming girl. Richard had set all his hopes on Mortimer and had looked forward to him taking over the family business interests. Richard had in fact made a will leaving everything to Mortimer. Mortimer's death meant that after Richard, there would be no one of the Abernethie name to come after him, to succeed to the fortune and control the business. Richard was therefore forced to change his will, thus setting up the complex web of suspicions that would be cast when later Richard died and it was thought the he had not died naturally.