Christopher states that many things are mysteries but that doesn't mean there isn't an answer - just that scientists haven't found the answer yet. He uses the example of ghosts, such as the one his Uncle Terry saw at the Greyfriars Shopping Center. Christopher believes scientists will discover an explanation for ghosts, as they have for electricity and lightning. However, sometimes a mystery isn't a mystery and he gives an example: involving the frog population for a pond at school. The fluctuation in the number of frogs every year can be attributed to a mathematical formula about animal populations, tied into population density and the application of a constant. When the constant is greater than 3.57, the population numbers stop being regular and become chaotic, as discovered by Robert May, George Oster, and Jim Yorke.
Notes - Christopher finds comfort in explaining chaotic experiences through mathematics. That is a way to try to understand things that would otherwise cause him mental discomfort.
Six days later, Christopher is able to return to his Father's bedroom. It's a Monday evening and Father has two emergencies that his business has to handle: Rhodri takes care of the first and so Father must take care of the second. When Father is gone, Christopher goes to his bedroom and looks into the shirt box: he finds forty-three letters in all and opens one to read. Dated May 3, Mother writes about getting a new fridge and cooker, and of how she looked at some old photos and remember what Christopher was like when he was younger.
Christopher reads another letter, this one where Mother explains why she left Christopher and Father to be with Roger Shears. She tells him that she wasn't as patient as father and they had many arguments; she spent more time with Roger as a result. Then there was an argument with Christopher where he accidentally broke her foot with a chopping board; soon after, when Roger said he was leaving for London and asked her to join him, she said yes. She meant to say goodbye but when she called Father he said she couldn't come back or talk to Christopher. She asks Christopher to write to her, or call.
Christopher opens a third envelope, this dated September 18, where Mother talks about getting a job with Perkins and Rashid, a Chartered Surveyors. A fourth letter, dated August 23, begins with an apology for not writing the previous week. She had been to the dentist and taken a good deal of painkillers... Before Christopher can finish the letter, however, he feels sick. He realizes Mother had been alive all this time and Father had lied. He rolls onto the bed and curls up in a ball, but there is a gap in his memory. It's a large gap, as when he wakes it's dark outside and he had been sick all over the bed and himself. Christopher hears Father coming into the house and when he comes to the bedroom, sees what has happened. He apologizes to Christopher and tries to explain that he did it for Christopher's own good and that it was an accident. When Mother left, he didn't know what to say so he told Christopher she was in the hospital and from there it went out of control. He tells Christopher that they need to clean him up, and so Father starts a bath and carries him to the bathroom. Christopher doesn't scream or fight or hit.
Notes - The spelling in the letters of Christopher's mother is often flawed, indicating a lack of education. Christopher's inability to fight at being touched shows how traumatic the revelation about his mother proves to be for him. In effect, the second mystery is solved almost immediately after it's discovered by Christopher.
When Christopher first started in school, his main teacher was Julie. One day she held open a Smarties tube and asked him what was inside; he said Smarties but it turned out to be a pencil. She then asked if his mother came in and was asked the same question, what would she say? Christopher answered, "A pencil." At that time, Christopher did not understand about other people having minds, something Julie believed he'd have difficulty with but which he now understands. He likens this to how people think their minds are different from computers but it's really the same. An experiment shown on a TV series called How the Mind Works explains how the eye processes changes in its view through flicks called sacades, creating a sense of continuous motion for the mind viewing the image. Further, people can have pictures on the screens of their minds that aren't what they are looking at, which gives them an advantage over animals. As a result, people believe there is someone in their heads, a homunculus, which observes brain activity and sets them apart from computers. However, Christopher says, the homunculus is just another picture on the mind's screen. Also, people think they're not like computers because they have feelings and computers don't, but Christopher sees that as just another screen responding to a certain event or image.
Notes - What Christopher describes is the homunculus fallacy, which argues that there is an agent within the mind that observes the behavior of the mind. However, such an argument leads to infinite regress - that is, there must be another agent that controls the agent making the observation, and in turn that agent needs its own agent, and so on.
Father gives Christopher a bath, dresses him in clean clothes, and places him in bed. He asks Christopher if he's had anything to eat but he doesn't respond. When Father goes to put the dirty clothes and linens in the wash, Christopher tries to clam himself by doubling 2's in his head. When Father returns to check on Christopher, he continues not to respond. Father sits next to him and confesses to killing Wellington. Christopher at first thinks this is a joke since he doesn't understand jokes, but Father continues to talk. He explains how he thought the friendship with Mrs. Shears would continue but she said something hurtful and seemed to care for the dog more than Father and Christopher. After one argument with Mrs. Shears, Father was so angry that he took it out on the dog, which is when he killed Wellington.
Father holds out his hand to touch fingertips and thumbs with Christopher, but he screams and pushes himself away from Father. Father apologizes again and leaves the room. Christopher is now scared: Father murdered Wellington, which means he could murder Christopher as well. However he couldn't leave immediately, he had to wait until Father was asleep. At 1:20 a.m. he checks to find Father asleep downstairs. Making sure of this, he packs some items and takes Toby in his cage to the garden, where he hides in a gap between the shed and the fence. Here he feels safer and wonders what to do next.
Notes - Christopher equates the ability to murder a dog with the ability to murder a human, which isn't surprising since Christopher has more respect for dogs - who are easy to understand - than humans, who are more difficult to understand.