Heroes: Saving Charlie (Part 3)

As I near the end of this great book, one question gnaws at my brain. The same question that occurred to me as soon as I started reading. What goes wrong? Hiro and Charlie are going to Japan. Charlie won't be murdered. They'll live happily ever after. But they won't. I know this already. What's going to destroy the perfect situation and force Charlie to stay home from their trip? I can't wait to find out.