Siobhan asks why he has a bruise on his face, and he tells her what happened. They talk about it for a while and then Siobhan asks if he's scared to go home again. Christopher says he isn't, and so they drop the subject.
When he gets home from school that day, Christopher starts looking for his book. It isn't in the garbage can, so he looks all around the house. Eventually he's looked everywhere but his father's bedroom.
He's very careful not to move anything, or else his father will know he was snooping around in there, which clearly won't make their situation any better.
Finally, underneath a toolkit at the bottom of the cupboard, inside an old shirt box, he finds his book. Ta-da!
At that moment, he hears his father's van pull up outside the house.
Christopher knows he has to think fast. He figures that his dad probably won't throw the book away, so he doesn't have to worry about losing it.
He'll start another book, and maybe get this one back one day when his father is less angry.
Right when he hears the car door slam outside, he sees an envelope with his name, "Christopher Boone," written on the front.
Then he sees there's a whole big stack of envelopes, all addressed to him. And the handwriting is all the same, with the letter I dotted with circles instead of dots.
There are only three people he knows who draw circles above the letter I like that: Siobhan, another teacher, and his mother.
He quickly takes one envelope from the stack and puts everything else back in the cupboard. This kid's a quick thinker.
When his father calls his name, he doesn't answer: Christopher doesn't want him to know he's in his room. Instead takes the envelope into his room and hides it under the mattress before heading downstairs.
His father makes him dinner and they're very nice to each other while they eat – it's really quite sweet.
Then Christopher goes back to his room, shuts the door, and takes out the envelope.
He wonders whether it's okay for him to open it: on the one hand, he took it from his father's room; on the other hand, it's addressed to him (not his dad).
He opens it, and reads it.
The author apologizes for not having written in so long, but she's been very busy. She writes about her new job working as a secretary in a factory, and about the new flat she and someone called Roger have moved into in London.
She says she realizes that Christopher is probably still angry with her, but she would love to hear from him.
And – here's the kicker – it's signed, "Your Mum."
Although we're starting to put the pieces together, Christopher is still confused, since his mother never worked as a secretary in a factory, and never lived in London.
He looks at the postmark on the envelope, and sees that it was sent eighteen months after his mother died.
Okay, now he's really, really confused.
At that moment, his father walks in and tells him that one of his favorite TV shows is on, if he wants to come down and watch it.
Christopher stays in his room and tries to figure out what in the world is going on.
Then he gets really excited, because now he has two mysteries to solve. Sherlock Holmes, here we come!
Christopher decides that the next time his father is out of the house, he'll read the other letters. But for now, he goes downstairs to watch TV. We totally approve.