A senior demon, Screwtape has corrupted thousands of humans, leading them away from the path of righteousness and causing their eternal damnation. For this, he has been praised and promoted often. As a high-ranking demon, Screwtape assumes the role of mentor to his young nephew, Wormwood. In a series of thirty-one letters to Wormwood, Screwtape offers advice to the inexperienced demon, who has been charged with the corrupting the soul of a young man referred to as the "patient." In the letters, Screwtape describes some of his heartless methodologies and reveals himself to be an utterly reprehensible character—which is understandable, given his status as a demon. Nevertheless, the philosophical Screwtape harbors curiosity about God and Christianity. He wonders how God can love human beings and expresses an interest in converting to Christianity. In the end, however, he's perfectly happy to eat his nephew, who has failed to tempt the patient.
Wormwood is a "junior tempter" charged with what should be a simple enough case: the corrupting of a young man who has shown weakness and a lack of moral fiber. Wormwood has attended the Satanic equivalent of college, yet remains largely ignorant of the methods that a senior tempter such as Screwtape would use to tempt a human. Wormwood himself never appears in the book. Instead, C. S. Lewis characterizes Wormwood through Screwtape's letters to his nephews. With Screwtape's letters, readers piece together a narrative in which Wormwood repeatedly tries and fails to corrupt his "patient." It quickly becomes clear that the young, inexperienced Wormwood is merely a foil for Screwtape, whose own actions and beliefs dominate the narrative. Wormwood's inevitable failure to corrupt the patient results in a terrible punishment: Screwtape will be allowed to eat him for lunch.
Like Wormwood, "the patient" has no voice in the narrative and is described solely through Screwtape's letters. Early on, the patient is described as a weak young man of little moral fiber who should be easily tempted by Wormwood. Over time, however, the patient comes to embody the Christian virtues of loyalty, faith, and bravery as he grows up, joins the war effort, and marries a devout Christian who guides him on the path to righteousness. The patient dies in the war, having accepted God into his life and recognized Wormwood for the demon he is.
The Patient's Mother
The patient's mother is a minor character in The Screwtape Letters. Screwtape describes her as a fussy, irritable who suffers from the sin of gluttony. She is the embodiment of many clichés about English mothers.
The Married Couple
The patient befriends the married couple early in life. Their sarcastic remarks about the Catholic church lead the patient astray, nearly converting him to atheism. Their behavior upsets the patient, and he breaks contact with them after a few chapters.