Martin Scorsese's latest has a whopper of a conclusion. It's almost a note-perfect adaptation of Dennis Lehane's book. "Almost" because there's one comment made at the end which throws the entire house of cards constructed by the author into question. Lehane already told us that he stays out of the writing process once an agreement has been made to adapt one of his books. But he did share his thoughts on the slightly altered ending seen in the film. Seriously: don't hit the jump if you haven't seen this movie.

SPOILER WARNING: "Shutter Island" concludes with the revelation that Leonardo DiCaprio's U.S. Marshal Teddy Daniels is in fact an alternate persona constructed by former U.S. Marshal and current Shutter Island inmate Andrew Laeddis. The entire investigation that unfolds over the course of the story was in fact an elaborate ruse designed to rattle Laeddis so much that he puts his Daniels persona to rest.

In this book, there's no question about how the ending plays out. Laeddis, seemingly on the road to recovery after his shocking ordeal, goes to sleep. He wakes up and meets with his doctor, who had been playing the role of his partner for the "case," outside the main facility. As the two sit there, it becomes clear that Laeddis has once again lapsed into his Daniels persona, essentially sentencing himself to a lobotomy.

The film is more ambiguous. Things play out similarly, but as Laeddis/Daniels sits and has a smoke with his doctor/partner, he asks the question "Would you rather live as a monster or die as a hero?" This raises the possibility that his relapse is in fact intentional, that Laeddis is so tired of being sick, he longs for the blissful ignorance that a lobotomy will bring.

We asked Lehane for his thoughts on the altered ending in an interview last week. "I would say that line, which comes across as a question, he asks it sort of rhetorically," he explained. "Personally, I think he has a momentary flash. To me that's all it is. It's just one moment of sanity mixed in the midst of all the other delusions."

"When he asks the question, he does it in such a way that, if he were to say it as a statement... then there's no solution here but to stop the lobotomy. Because if he shows any sort of self-awareness, then it's over, they wouldn't want to lobotomize him. My feeling was no, he's not so conscious he says 'Oh I'm going to decide to pretend to be Laeddis so they'll finally give me a lobotomy.' That would just be far more suicidal than I think this character is. I think that in one moment, for a half a second sitting there in that island he remembered who he was and then he asks that question and he quickly sort of lets it go. That was my feeling on that line."

That's about as detailed an explanation as a fan could hope for. It's also a sensible read, even if you don't agree with the decision to make the change. Lehane was and is okay with it though.

"I liked that line when I read the script," he said. "There was just some debate as to how much of a question it is and how much of a declarative statement. In the end they went with it being a question, which I think is important."

Have you read the book? What do you think of the movie's ending? How does it compare to the more certain picture painted in the book?