TL;DR. There are two kinds of fake ticking clock and they run on different rules. The first is a lie told inside the story, where a character manufactures a deadline to move somebody else, and it works when the lie costs whoever believed it. The second is a lie the writer tells, inventing pressure over real events that never came with any, and it works when that pressure dramatizes an outcome that actually happened instead of replacing it. Both fail the same way, which is the deadline landing with nothing at stake, so the scene exhales and the reader feels handled. Find out who your clock is really running for.

What's the difference between a clock a character fakes and one the writer fakes?

Inside the story, a false clock is a tool somebody is using on somebody else. A character invents a window, sells it, and watches the mark move faster than he should. That clock has an author in the room, the author has a motive you can dramatize, and the reveal is available to you as a scene later.

The writer's false clock has no author in the room. You built it at the desk because the material didn't supply one, nobody in the story knows it's manufactured, and there's no reveal available, because cashing it in would mean telling the audience you were the one squeezing them. So it has to work quietly and pay for something real.

I keep the two in separate drawers, because "The Sting does it" is no defense of a clock you invented over a true story.

How does a character-built clock pay off?

The Sting. David S. Ward wrote it, George Roy Hill directed. Lonnegan spends the back half running on pressure the men he's trusting built for him, one enormous bet on a wire con, with the instruction arriving at the last possible moment. The payoff isn't that the clock was fake. It's that "place it on Lucky Dan" meant the horse comes in second, and we were watching the wrong man sweat the whole time.

Nine Queens. Fabian Bielinsky wrote and directed. The deal has to close tonight because the Spanish collector, Vidal Gandolfo, is being deported in the morning, and every bad decision the lead makes gets bought with that one sentence. Then the warehouse door opens and we learn the deportation, the collector, the motorcycle thieves and the girlfriend were all one apparatus pointed at him.

House of Games. David Mamet wrote and directed. The pressure on Margaret Ford is a vanished briefcase holding eighty thousand dollars borrowed from the mob and a man leaving for the airport tonight, and when she learns the hotel room was staged, every beat she sat through reorganizes itself. All three work the same way. The lie is expensive for whoever swallowed it, and the reveal hands you a second story you didn't know you were watching.

Why did Argo need a clock the history didn't have?

Argo. Chris Terrio wrote it, Ben Affleck directed. The airport sequence at the end is invented. No confrontation at the gate, nothing chasing the aircraft down the runway. The CIA's own public account says the six passed customs and immigration without trouble, and one of the real escapees, Mark Lijek, put it plainly: the immigration officers barely looked at them and they were processed out in the regular way. The film also stages a last-minute cancellation that Mendez defies. Carter's authorization was delayed by roughly thirty minutes, and that happened before Mendez ever left Europe. The real escape was an early morning Swissair flight out of Mehrabad, timed so the airport would be half asleep, and the only real delay was mechanical.

Terrio built a clock because the facts didn't come with one, and that's allowed. A real escape that goes smoothly is a wonderful thing to live through and a terrible third act. The question is what you owe for the loan.

Where's the line on compressing real events?

My working line is to invent texture, not stakes, and never to invent a villain out of a living person.

The Imitation Game. Graham Moore wrote it, Morten Tyldum directed. The film gives Turing a deadline enforced by Commander Denniston, who threatens to defund the machine and later has it destroyed. There's no record of any of it. Denniston recruited Turing before the war and backed the codebreakers, and his grandchildren called the portrayal an unwarranted sideswipe at his memory. L.V. Anderson, writing in Slate, described the film as injecting conflict where none existed.

Sully. Todd Komarnicki wrote it, Clint Eastwood directed. The clock is an adversarial inquiry closing in on a pilot, and it was manufactured. The NTSB's lead investigator on the real accident, Robert Benzon, said they weren't out to embarrass anybody, and after the film came out he said its treatment of the board went well beyond cinematic license. Sullenberger asked that the real investigators' names come off the characters, because he didn't think of them as prosecutors. That's the invoice arriving at somebody's actual reputation.

Compare Bridge of Spies, written by Matt Charman and Joel and Ethan Coen, Steven Spielberg directing, which pulls the Berlin Wall going up into Donovan's trip even though Frederic Pryor says he was on vacation in Denmark while it was built. The texture is compressed, the stakes are true, and nobody living gets turned into a heavy.

How do you plant and pay off a false deadline on the page?

Four things, and they're all mechanical.

Put the number in a character's mouth, not in action lines. A clock somebody says out loud has a speaker, and a speaker has an interest. A deadline that exists only in description belongs to nobody.

Make the mark repeat it. The moment Lonnegan starts talking about his own window, the clock has moved from a claim into a belief, and beliefs can be punished.

Build one cost before the window closes. Somebody cancels something, spends something, tells a lie they can't walk back. The deadline needs a receipt or the reveal has nothing to collect.

Pay it off with new information, not relief. The reveal should re-read a scene you already wrote.

For an authorial clock the mechanics invert. You can't plant it as a lie, so you plant it in procedure: a flight time, a signature due before a shift change, a window somebody in the room would be tracking anyway. Then make sure what it accelerates is the true outcome and not a different one.

What does the cheat look like?

The deadline arrives, turns out not to matter, and the scene relaxes. You held a reader for twenty pages on a number and then told them the number was nothing. Nobody calls that a twist.

The second failure is a clock with no owner. If the pressure belongs to no character and to no part of the record, it belongs to you, and the reader will feel your hand on their back.

Before you call it a clock, run this checklist

Who said the deadline out loud, and what do they get if the other character believes it?

Does the character under pressure ever repeat the number back, in their own words?

What does somebody spend, cancel or confess because of this clock, before it runs out?

If the clock is fake, who pays when it's revealed, the person who built it or the one who swallowed it?

Does the reveal change the meaning of a scene I already wrote, or does it only release tension?

If I invented this clock over real events, is it accelerating what actually happened or replacing it?

Have I built a named real person into an obstacle they never were?

If I cut the deadline entirely, does the sequence still have a decision in it?

A real clock buys attention and pays it back with a decision, while a false one borrows that attention against a promise you may not be able to settle. Open your draft to the page where the deadline first gets spoken, write the speaker's name in the margin, and if the only name you can put there is yours, cut the number and go find the decision underneath it.

Sources. Credits and plot for The Sting, Nine Queens, House of Games and Argo, and the historical accuracy records for Argo (including Mark Lijek's quote), The Imitation Game (the Denniston family's response, L.V. Anderson in Slate), Sully (Robert Benzon's statements, Christine Negroni in the New York Times) and Bridge of Spies (Frederic Pryor on the Berlin Wall timeline): all from the respective Wikipedia entries. The customs crossing, early Swissair booking and mechanical delay in the real 1980 exfiltration come from the CIA's public account, "Argo: The Ingenious Exfiltration of the Canadian Six," at cia.gov. Argo's screenplay is credited to Chris Terrio, adapting Tony Mendez's memoir The Master of Disguise and Joshuah Bearman's 2007 Wired article.