The ending of this story is really interesting to me. Christopher and his mother have made their way back to Swindon, and Christopher is living with his mother in a small, dingy boarding house of sorts. After the intial fights between his parents, things have smoothed out, and he passes his math exams with the highest grade. He is rebuilding his relationship with his father, and I love the last few sentences he writes.

"And then I will get a First Class Honors degree and I will become a scientist. And I know I can do this because I went to London on my own, and because I solved the mystery of Who Killed Wellington? and I found my mother and I was brave and I wrote a book and that means I can do anything." (221 Haddon)

There's so much real, raw hope in that statement. Christopher's determination is pure and fueled by his experiences, and his growth. It's really, really amazing. Definitely a fitting ending to such a tumultuous story.