Christopher continues to read the letters and learns that is mother is in fact not dead and that his father lied to him. His father also confesses that he is the person who killed the dog.
After his father goes to sleep, Christopher decides to run away to live with his mother in London in fear that his father might hurt him.
A police officer stops Christopher because he looks lost and Christopher explains that he is going to live with his mother but he doesn't know how to find the right train so the officer assists him.
The police officer then finds out that Christopher's father has reported him missing and the officer decides to ride with Christopher to bring him back to his father. But Christopher decides to hide in the bathroom so he loses the officer and continue traveling.
When Christopher finally makes it to his mother's he explains everything to her and she allows him to stay with her and Mr. Shears.
After the police allow Christopher to live with his mother since it's what he wanted, his father decides to get Christopher a dog that must stay at his house since his mother's house is too small. This is to keep Christopher tied to his father and give him a reason to come visit.