Heartwarming / The Curious Incident of the Dog in the Night-time
Christopher reconnecting with his father after everything that's happened. It was clear that there was a real risk that the estrangement might have been permanent, and his father was all too aware of that. Even though Christopher can't recognize the signs, it is clear to the reader how much it means to him when Christopher acknowledges his presence again.
Christopher helping his father plant the vegetable garden is sweet, especially since it's a far cry from the former screaming whenever the latter was in the room, showing that their relationship is slowly healing.
Christopher's father getting him a new puppy near the end of the story.
Christopher's mother kicking Mr. Shears out of the house also near the end of the story. As with the previous, this is her way of making up for what she has done.
You must admit the relationship Christopher has with his parents is pretty heartwarming and downright awesome. They both have showed abuse towards their son, but whilst, they both make all efforts to tell him that they love him and show it. They both feel remorse for previously hitting their son, and they both scold others (for example, other authority figures) when they stress him. His parents prepare his food the way he likes it, and though both want to hug their son, they touch his fingertips just to show him that they love him and care. It is a good thing Christopher reconciles with his parents at the end, if not slowly. Not every child and parent has that bond, and quite obviously with abusive parents.
The elderly neighbor, she acts as a grandmother towards Christopher, saying that he can count on her, but unfortunately, due to his lack of trust in people, he does not trust her that much, despite how good she is to him.
The relationship Christopher has with his teacher.