We Have Always Lived in the Castle by Shirley Jackson (1962). At least I think he did -- it has been in my pile for so long that neither one of us can really remember how I got it. I do know that I have been excited to read more Shirley Jackson ever since Dan lent me The Haunting of Hill House, and I can't believe it took me so long to get to this one.
Six years ago, four members of the wealthy Blackwood family were killed at the dinner table after their sugar bowl was laced with arsenic. The younger sister, twelve-year-old Mary Katherine (known affectionately as Merricat), had been sent to bed without supper, and so avoided the deathly sugar bowl. The older sister, Constance, prepared the meal and didn't take any sugar on her berries, and so became the prime suspect, although she was eventually acquitted and sent back to live with Merricat and their Uncle Julian. Julian survived the arsenic, but was permanently disabled and weakened after the poisoning.
The Blackwoods are hated by the people in the village, both for their wealth and for getting away with murder. Constance refuses to leave the estate, and Merricat is teased and harassed on her twice-weekly trips to the village for food. Still the two women and the dotty old man are happy in their isolation and seem willing to continue on like that indefinitely, until Merricat senses that things are about to change. That change is the arrival of their estranged Cousin Charles, and what he sets into motion can never be undone.
This is a relatively simple story that is elevated by the decision to give us as a narrator the increasingly unreliable Merricat. Ordinary actions and coincidences take on a sinister meaning through her mystical mind, and anything that moves to disrupt the sanctuary of her home or the routines of her beloved sister is treated severely. Like The Haunting of Hill House, the mystery in We Have Always Lived in the Castle is secondary to the psychology of the characters. This was Jackson's last novel, and it should move its way up to the top of every reader's pile