Shutter Island (kinda sorta possible spoilers herein, maybe)

So this afternoon, I ventured out to a engage in one of my favorite weekend relaxation activities: reading while bellied up at a bar.  I actually did this at two bars, but at the first I only had a sandwich and a regular iced tea, so I don't know if it really counts, although I'll be the first to admit that that's probably very much beside the point.

The book of choice was Shutter Island by Dennis Lehane, a few of whose other books I've very much enjoyed, particularly The Given Day.  And his writing on HBO's "The Wire" was, well, I'd hardly be first to extol the vitures (e.g., he wrote one of those lines from the show that I think of often, whether I'm at work or reading the newspaper: "It's Baltimore, gentlemen; the gods will not save you.")

So, about Shutter Island...

Actually, I can't go any further without warning that I'm about to reveal a possibly important aspect about the structure of the book and my guess about what it means.

[spoiler space]

[/spoiler space]

I'd barely begun reading the book when someone took it upon himself enough to inform me that the book had one of the "most mind-blowing twist endings" he could recall.

Well, isn't that just freakin' great.  Thank you so much.  Can I repay the favor by sneezing on that lunch of yours?

I've gotten through the first 100 pages, and I'm enjoying the story immensely, so far, but I'm reading it with "twist ending" in mind.  In fact, when I read the single-sentence paragraph that ends page 30 of the Harper Fiction paperback edition ("And he turned and led the way through the gate, and the gate was closed behind them."), I immediately felt certain that I knew what the twist was.  And most everything I've read since then has only reinforced my guess that Teddy Daniels is actually an inmate-patient at Shutter Island for having set the fire that killed his wife and three others years before this story is supposedly set.

I have plans for tonight and nearly a full day planned tomorrow, so I likely won't be able to find out if I'm right until next weekend.  But I'm dying to know.  If it turns out that I'm right, I might just have to make it my mission to track down the s.o.b. who spoiled it for me.  But I might still be able to enjoy the story, and might even enjoy watching how Lehane was able to control the story while leading readers down unexpected paths.

UPDATED 26-SEPT: Just finished the novel.  Turns out that while I wasn't right, well, I had, in fact, been right.  Tomorrow, I'm gonna have to figure out how I go about hunting down that s.o.b.  Good book, though.  Might have to rent the movie this week to see how faithful it is.