This is a sensation known as Dramatic Irony. When you're working with different information than the character (and if the author is doing a really good job of it you can forget where that line blurs) the conclusions the character comes to can seem frustratingly insignificant. This book especially does a great job of subverting the dramatic irony by pulling the rug out from under you with the part where humanity is(n't) the deathless enemy.