Christopher remembers the day two years ago when Mother died. He came home from school and found the house empty. When his father arrived home later, his father made several phone calls to locate her and then went out for a few hours. When he returned, he told Christopher that Mother was in the hospital because of a heart problem and that Christopher wouldn’t be able to visit. Christopher decided to make her a get-well card, and Father promised to bring it to her the next day.
The morning after Wellington’s murder, Christopher spots four red cars in a row on his bus ride to school, making the day a Good Day. Christopher explains that he ranks the day according to the number and color of the cars he sees on his way to school. Three red cars in a row equal a Good Day, and five equal a Super Good Day. Four yellow cars in a row make it a Black Day. On Black Days Christopher refuses to speak to anyone and sits by himself at lunch. The school psychologist, Mr. Jeavons, points out that Christopher’s system surprises him since Christopher is so logical. Christopher says he likes to have an order for things, even if the order isn’t logical. He acknowledges it makes him feel safe. He says Father puts his trousers on before his socks every morning because it is his order, not because of logic. Christopher decides that he will set out once more to find Wellington’s killer because it is a Good Day.
Christopher recalls that Mother died two weeks after going into hospital. He never saw her there, but Father said that she sent lots of love and had his get-well card on her bedside table before she had an unexpected heart attack. Her death surprised Christopher because she had lived an active and healthy life and was only thirty-eight years old. On the night she died, Mrs. Shears came over and held Father against her chest to comfort him. She also cooked dinner, and afterward Christopher beat her in Scrabble.
Back in the present, Christopher sets out to investigate Wellington’s murder. He knocks on Mrs. Shears’s door, and when she answers, explains that he did not kill Wellington. Mrs. Shears, however, closes the door in his face. Christopher walks back down the sidewalk, and he can see Mrs. Shears’s shadow as she watches him through the frosted glass of her doorway. He waits until she leaves, then sneaks around the side of her house and jumps the garden wall. In the garden he finds a locked shed. He looks through the window of the shed and sees the garden fork used in the murder. Christopher concludes that the murderer had to know Mrs. Shears in order to have access to her garden fork. Just then Mrs. Shears discovers him in her garden and threatens to call the police. Christopher goes home, happy to have discovered a clue.
Christopher remembers a vicar called Reverend Peters who said heaven was a different kind of place than our universe. Christopher believes that heaven doesn’t exist. He reasons that heaven could possibly lie on the other side of a black hole, but for the dead to get there they’d have to be fired off into space by rocket.
Christopher has a strong desire for order, and he works to remove any sense of disorder from his life. For instance, his system for determining how good the day will be, despite its apparent illogicality, provides him with a sense of control over the ambiguities and uncertainties he encounters every day. For similar reasons, Christopher cannot accept the idea of heaven’s existence since it violates everything he knows about the universe, meaning if heaven exists the order he knows is wrong. As Christopher admits in his conversation with Mr. Jeavons, order makes him feel safe, even when that order is not logical. Though Christopher justifies the irrational aspects of his need for order, such as using the colors of the cars he sees to forecast whether the day will be good, by saying that everyone behaves in this way, the reader can see that Christopher isn’t really interested in how logical his system is. He uses it because the sense of order it gives him makes him feel safe.