The first causal circumstance that sets a plot in motion is where the reader becomes aware of the protagonist's predicament, often when the protagonist becomes aware of the predicament also, but not necessarily so.
The inciting moment is when the motivating forces of antagonism come into play and when the protagonist first seeks to address the predicament. Tension begins to rise with the inciting moment. The forces of antagonism can be in opposition or parallel with the protagonist's purpose as related to the predicament.
The predicament and what the protagonist is doing about it is what a reader needs to know, not much else is essential beyond the outcome being in doubt through to the climax, and that the predicament be satisfactoriy resolved for good or ill, successful or failed accomplishment of the desire derived from the predicament.
What the PoV knows. If the PoV wouldn't naturally (or believably) be thinking of it, the reader shouldn't know. If the PoV is thinking about it (or would naturally be) you cheat the reader by not telling them.
I've run across a few stories where a POV "remembers" something right at the climactic moment. The only time that worked for me as a reader was when it had been revealed earlier in the story, and I got to "remember" too.
I recently read a book, where a major character hatches and executes a very clever and involved plan to further his cause. The problem for me was that the book spent a fair amount of time in the guy's POV, detailing the outward deception facet of his plan, but his ultimate intentions were not revealed (the plan involved betrayal). Really ruined what could have been a good story. I believe that author would have been better served to stay out of that character's POV.
Of course, he wasn't much into crime novels, and he also said that a truly great writer MUST be a graduate of higher education. So take the above with as many grains of salt as necessary.
I'm inclined to agree with dee_boncci's take on it.
This is used all too often in film and TV and it is a cheap, annoying method of creating tension in the viewer. It's also often used in short fiction, where a fact is "revealed" at the end that changes the tone of the story, but the only reason that fact was concealed was in order to get the "aha!" moment.
Easier said than done, my friend. I am always being surprised by my charaters and what they do, say, and reveal. My current WIP has evolved from a short story idea into a novel that promises to be the first in a trilogy. I've got to stop letting my characters write the outline.
Where Eagles Dare has a scene where Richard Burton tells Clint Eastwood, "You asked me why you were brought on this mission..." and the camera cuts away. (That's not an exact quote, by the way, but the gist is there.)
Yeah, it was a cheat, but I think it worked because we put ourselves in the Burton's character's hands, and we trusted that character to eventually explain the situation. It also helped that though there was a mystery, the action and suspense resulted more from the storming of the castle (so to speak) than the mystery of WHY they were storming the castle. It also helps that when we the viewer finally get the reveal, even the Eastwood character looks as surprised as the viewer. It's obvious Burton didn't tell Eastwood everything.
I guess that just means that there's always an exception to the rule. Hmmmmm. The Murder of Roger Ackroyd may be another one.
Cheyne, letting your characters drive can really do great things for a story. I think it was Stephen King who said that he starts off with characters and a situation and lets the characters steer the story.
dee_boncci, that seems to be the way my mind has been going as of late, good to hear it backed up.
Of course, if the story doesn't work after the first draft, then the author is going to have to fix it in the rewrites, but I don't think the characters can surprise the author all that much by then.