Last week I cautioned that it's not often a good idea to let the audience get too far ahead of the characters in the story. Many times, it can be frustrating for a viewer to have to wait for the characters to "catch up" to them, resulting in a less compelling viewing experience. However, I'd say there's at least one very good exception to that rule. I'll yield the floor to Alfred Hitchcock, master of suspense.
"There's no emotion in a who-dun-it because you withhold information from an audience. The element of suspense is giving them information.
"[Suppose] you and I are sitting here . . . . suddenly a bomb goes off and up we go, blown to smithereens. What have the audience had while watching this scene? Five or ten seconds of shock. Now we do the scene over again, it's a five minute scene. You and I are talking about football, something very innocuous, but the audience are informed by a method unknown to us that there's a bomb under the table and it's going to go off in five minutes.
"Now this innocuous conversation about football becomes very potent. 'Don't talk about football, there's a bomb under there,' that's what they want to tell us, as the bomb ticks away and we keep telling the audience there's a minute to go; half a minute and finally ten seconds. That is when it must not go off. If we let it go off, the audience will be as mad as hell with us, they'll be disgusted. They'll say, "Don't go and see that movie or that play".Your toe MUST touch the bomb at the last minute, you must look under the table, grab the bomb and throw it out of the window, then it can go off; but you and I must be saved. An audience needs that relief after you've put them through the ringer."
(Source: http://www.on-cue.org.uk/articles16.html, originally published in 'Heard in the Wings" edited by Roderick Bloomfield, 1971.)
The key thing to remember here is to take advantage of the suspense that is generated when the audience is ahead of the characters. One such example I remember well is the reaction the multiplex crowd had the first time I saw Air Force One. The premise is that terrorists have taken over the President's plane, and unbeknownst to anyone, one of the Secret Service agents is a turncoat who has aided the terrorists in taking over the plane. For much of the first half, this agent is with all the other hostages, as if he was one of them.
Then comes the moment when Harrison Ford, playing the President, gets to the hostages. Guess who he gives his extra weapon to? The Turncoat Agent. I don't think I've ever heard an audience react so aggressively as when Ford gives his enemy a weapon. It felt like the whole room was shouting "NO!" They knew that it wouldn't end well.
Basically, if your viewer is ahead of the audience, craft scenes that has characters making fatal mistakes that they wouldn't make if they knew what the audience did.