Christopher’s mother, we learn, is really alive. The letter is dated a year and a half after she supposedly died. In finding the letter and what it contains Christopher’s world is thrown off balance. His brain cannot process the contradictory facts so he decides that the letter is for a different Christopher. He is incapable of believing that his father, and mother for that matter, would lie to him purposefully. He also determines that he’ll have to go back and look at the other letters since one is not enough proof.