To what extent does Haddon present Christopher as courageous in the novel?
Haddon presents Christopher as courageous because Christopher is willing to go beyond his usual boundaries to find out the truth about who killed Wellington, the dog, and about what happened to his mother. When Christopher realizes that his neighbor, Mrs. Shears, is lying to him about what happened to Wellington, he decides to find out what really happened. He says that he "felt happy because I was being a detective and finding things out" (Chapter 59). Carrying out this type of detective work is difficult for Christopher, as he has a form of autism spectrum disorder and cannot always navigate the outside world, despite his intelligence in areas such as math.
In carrying out his detective work, he has to speak with people he does not know, which is very difficult for him. He says in Chapter 67, "So talking to the other people in our street was brave. But if you are going to do detective work you have to be brave, so I had no choice." While facing new situations is daunting to him—as he can't even stand to have the furniture moved—he also decides to head to London to look for his mother. This journey involves moving well beyond his comfort zone, but he is motivated to find out the truth about his mother. In this sense, he is courageous because even traveling on a train and going to a new place are undertakings that are very novel and frightening for him.