Christopher's father gets him all cleaned up and asks if he's had anything to eat today. He doesn't respond.
His father leaves the room, and Christopher just sits on the bed, staring at his knees.
He "doubles 2s" (that is, does 2 x 2 x 2 x 2 x 2 in his head) and gets to 33,554,432. (!) He says usually he gets much farther, but right now his "brain [isn't] working very well" (167.10).
Eventually Christopher's father comes back and says he wants Christopher to know that he can trust him. He knows he messed up, but it's not easy telling the truth all the time, and he's really doing his best.
He promises he's going to tell the truth from now on – about everything, always.
Then he tells him that he was the one who killed Wellington, the dog.
Christopher thinks he's just kidding, but he's not. His new truth streak is the real deal.
Christopher's father explains, very slowly and painfully, that when his mother left, he and Mrs. Shears started spending time together, and he was really hoping that they would become a couple, and that she would move in with them.
Instead, he and Mrs. Shears ended up arguing a lot. She said some mean things about Christopher and in the end seemed to love her dog (Wellington) more than she cared about either of them.
So, one night, after he and Mrs. Shears had an argument, he saw the darn dog in the yard and just snapped.
He says he couldn't help himself, and that he and Christopher really aren't so different.
He apologizes again, very sincerely.
This is the point when Christopher realizes he isn't joking. This is definitely a lot to take in all at once. This was his whole mystery, after all.
His father stands up, takes a deep breath, and walks out of the room. Christopher stays seated on the bed.
He sees Toby in his cage, staring through the bars.
Christopher decides he has to get out of the house. He very logically concludes: "Father had murdered Wellington. That meant he could murder me, because I couldn't trust him, even though he had said, 'Trust me,' because he had told a lie about a big thing" (167.30).
He decides to wait until his father is asleep before he tries to escape, though.
At 1:20AM, he still hasn't heard his father come upstairs to bed and he wonders if maybe he's fallen asleep downstairs. Or, perhaps he's hiding, waiting to kill Christopher. Uh oh.
He opens the saw blade on his Swiss Army knife so he can defend himself, just in case his father attacks him. He tip-toes downstairs and sees that his father is asleep on the couch (not waiting to kill him, it seems).
Christopher is really scared, and wonders if he's going to have a heart attack.
He puts on warm clothes, takes his special food box, and gets Toby's cage from upstairs. Then he walks out the back door into the backyard.
He thinks of going into the shed (because it would be warmer) but is pretty sure his father would look for him there. So he crams himself into a narrow space between the shed and a fence, lying down next to some junk.
That can't be comfortable, but a kid's gotta do what a kid's gotta do.
He eats some food, and wonders what to do next. We're wondering, too.