The Question and Answer section for The Curious Incident of the Dog in the Night-time is a great resource to ask questions, find answers, and discuss the novel.
The main "betrayal" Christopher suffers through is the knowledge that his mother is alive, and that his father not only blatantly lied to him for years, but also hid communication.
I'm sorry, which situation in the novel does your question pertain to? Chapter?
I can give you two quotes:
I decided that my best plan would be to wait for a really sunny day and then use my glasses to focus the sunlight on a piece of clothing and start a fire. I would then make my escape when they saw the smoke and too me...