Does critical choice exist? Or, tell Gandalf where he can stick his Fellowship

Once you start thinking about plot structure, you start to notice it everywhere. Through a whiskyish Christmas haze, I found myself counting down the climax-reversal-resolution at the end of Bridget Jones' Diary. I keep watching programmes like Lost with one mental eye on the plot structure, ticking off the arc points and thinking things like "Hmmm, the surprise is going to have to come soon".

It seems to me that critical choice is the most slippery of the eight-points. How is it possible that, in a linear narrative, that there can be any idea of choice at all? Obviously, in a strict sense, once you've read the book, there is no choice. The protagonist was always going to choose this way or that, and any sense that there was ever any chance of it going the other way has disappeared forever.

But there's a more subtle sense in which critical choice doesn't exist. Take Ted Kord in Countdown to Infinite Crisis. Why couldn't he have joined up with Maxwell Lord? The narrative establishing his character had made it clear that he was genuinely a hero, despite what his friends might think. If he had joined Lord he would have become a traitor, something which nothing within the story has prepared the reader for. The writer would have broken the unwritten contract with the reader, who would then feel short-changed.

The clues to the solution to the critical choice have already been established, and at the point of choice, the reader should be able to work out what the protagonist will do. In this sense, the critical choice doesn't exist at all.

Marionette questions whether Kord's conversion would be believable, either to Lord or the reader. Unless Lord was playing mind games, we have to assume that he thought Kord might convert, as otherwise there would be no point in even asking the question. Ongoing readers who know these characters probably wouldn't have bought the idea, I think, since it doesn't fit their idea of Kord's character. As a new reader, I would have accepted it, though, if the story had hinted at the idea that Kord might be capable of such a decision.

The critical choice in Lord of the Rings is Frodo deciding to take the ring to Mordor. A choice so critical, in fact, that he makes it three times - in the Shire, Rivendell, and on the Anduin. Each time, he makes, has to make, the decision to go on, no matter how badly events have turn. And it's fairly easy to guess that he'll make it, since the book is going to badly lose its direction if its hero (who, incidentally, isn't particularly heroic) decides to give up.

Yet Tolkien presents this choice three times. Why do we, the readers, not just think, "this is just bleeding obvious"?

I think the answer lies in the enormous suspension of disbelief which the reader is willing to undertake. We'll accept aliens, superheroes and speccy 13 year old wizards, all of which are blatantly ridiculous ideas. And we'll stick with it all, as long as the writer is good enough to sustain an illusion. We're willing to imagine that the events were witnessing are actually taking place in real time, that there is a geniune choice to be made.

It might seem that having the hero make a choice which goes against the grain of the story would be an exciting turn of events, but it seems not to be true. That would be the surprise in the arc, like Gandalf getting killed by a previously unmentioned Balrog. To maintain the suspension of disbelief, the decision in the critical choice has to fit with the reader's preconceptions. Ones which were fashioned by the writer themselves.

Which, to come full circle, is why you shouldn't analyse plots too deeply. If you're aware that what you're watching is a construct, rather than a series of events, then you just stop believing in it, and your enjoyment suffers. In the case of Bridget Jones' Diary, fortunately, there's not too much enjoyment to be had anyway.