When you first read the book, you care about what Acheron has to say about fate and free will. But thinking back on this quote, you realize that Nick is calling Acheron his "best bud." We're not sure when exactly they'll become friends, because they only hang out once in this book. It looks like they reach BFF status eventually, even though many people warn Nick to say away from Acheron.

These are the first lines of the book, which lead you to believe that fate and free will will be a more important theme than it actually turns out to be. Although there's a lot of talk about it early on—and maybe it will come back in a future book—it's a fairly minor theme in this installment.

Nick is required to say this, because a protagonist who thinks that has no control over his life would be pretty hopeless to read about. But what's the reality? How much control does Nick really have, if you think about it?

Does Nick not realize that he is contradicting what he just said about controlling his own destiny and life? It's possible the person talking here is actually future Nick, who goes by the alias Ambrose. By going back into the past, Nick wants to see if he can change his own destiny. (But then wouldn't the future be different, anyway? So how could future you go back in the past to fix things if things have already been fixed, and future you is already just fine? Don't ask us.)