No, I'm not going to answer the question; I'm not sure I know. I do know, though, that surprise is a central element in great literature. Something in it--formal, aesthetic, ideological, structural--has to surprise me. Of course to the novice reader everything is surprising: the lost dog actually made it home! The good guys won! Cinderella married the prince!
The more we read, the harder it is to surprise us. We understand how certain plots work, and we look for the ways in which they undercut their own structure, their own generic constraints. I was talking with a student today in my office and tried to explain it this way: genre and series novels please us by conforming to our expectations; great literature pleases us by subverting them.
That's not enough, but it's a start. And my most recent YA read, The Astonishing Life of Octavian Nothing, Traitor to the Nation, volume 1, satisfies in this regard. To call it a historical novel is to suggest that it dramatizes events and characters from history, and it certainly does so. But it does so in such surprising ways as to make the label seem limiting (though still, not inaccurate). The title character reveals himself so slowly, so carefully, that we are hooked before we know where we're going, and when we get there it seems absolutely inevitable that we would be there even though we could predict none of the turns along the way. If all you know of M.T. Anderson's work is Feed (and if you don't know Feed, you should), this book will surprise you simply with its setting: instead of the future, Anderson has chosen to imagine and realize the past. His love of language, though, remains: he is always looking for the ways in which we bend and shape the language to our own uses, and the limits that our language places on our ability to express--and even to think for-- ourselves. This novel also shares with Feed a concern with disease, with the importance of the body to the mind. And both novels question how democracy can really work, given the limits of the people in whom it (appears to) vest power.
But all that is simply to say that it made me think, and that it's going to keep making me think for a while.