Summer of Corruption: Apt Pupil (1982) is a novella by Stephen King, originally published in Different Seasons (1982).
Apt Pupil consists of 29 chapters, many (but far from all) of which are headed by a month. The story takes place in a fictional suburb of San Diego, called "Santo Donato", over a period of about four years, with most of the action taking place during the first year and the last months. It is the only novella in Different Seasons to be narrated in the third person.
Todd Bowden is thirteen and a smart kid with good grades. He and a friend rummage around in the friend's garage looking for comic. Instead Todd finds old war magazines with stories from the Nazi concentration camp and is fascinated by them. He begins to read everything he can get his hands on about World War II and the camps.
One day Todd sees an old man on the bus that he recognizes. After several weeks of discreet surveillance, he goes to the man's house and rings the bell. The sign on the door says ...