The physician-narrator recounts two unsettling house calls made three decades earlier when he began his medical practice in a remote part of Virginia. The doctor is asked to see Alan Jordan at the request of his wife, Judith. They live with their son and three elderly female relatives in a deteriorating house on a secluded estate known as Jordan's End. The Jordan clan is notorious for marrying their own relatives, but Alan wedded someone outside the family.

Judith is beautiful, and in the doctor's eyes, ethereal. Alan's infirmity began 3 years ago with brooding and melancholy but has now progressed to episodes of withdrawal alternating with agitation. A renowned psychiatrist from Baltimore evaluates Alan, deems his condition incurable, and recommends institutionalization.

Mental illness and insanity--the result of heredity and inbreeding--seem to affect all the Jordan men. Alan's grandfather and two uncles are in an asylum. His father died in one. After the narrator examines Alan, he gives Judith a bottle of opiate medication to help ease her husband's restlessness.

The doctor is soon called back to Jordan's End. He finds Alan's dead body in bed covered by a linen sheet and notices that the full bottle of medicine he left only two nights previously is now empty. The doctor cannot decide whether or not Judith has killed her husband nor does he really want to know.