-> '''Lochley:''' "Some alien weapons use a hell of a lot of energy to build up right before they fire. Smells like ozone."
->'''Gideon:''' "You don't have a gun on you, do you? I had to check mine at customs."
->'''Lochley:''' "No. I never needed one down here until you came along."
->'''Gideon:''' "What makes you think this has anything to do with--"
->'''Both:''' "[[OhCrap --ozone]]."
->''(Both duck as an alien weapon fires at them)''
-->-- ''{{Series/Crusade}}''

To an unaware observer, everything appears perfectly normal. Either no one's around, or everyone's going about their business as expected. There's no reason to think there's any danger nearby or that anything is out of the ordinary.

But there's one tiny little detail that suggests otherwise. Something out of place. Something... ''amiss''. It could be a moved piece of furniture, an insistent background noise, or a bit of speech of behaviour that is [[SpottingTheThread vaguely wrong]]. Whatever it is, it's so innocuous that our hero doesn't think much of it at first.

But at some point, the character has [[OhCrap a sudden realization]]: that detail is a sign of imminent danger. And sure enough, that danger will manifest itself within seconds. The character will either be captured or killed, or will survive through fighting, escaping, or ducking that [[BoobyTrap giant log]] right before it smashes into the wall.

To qualify for this trope, the detail must be unremarkable outside of story context, and must signal an imminent threat. Due to the TheoryOfNarrativeCausality, that threat will not materialize until the character has made the link -- even if the [[CeilingCling hidden]] [[{{Ninja}} ninja assassin]] could have sliced his head off as soon as he walked into the room.

Sometimes preceded by ItsQuietTooQuiet. If the danger in question is a bomb, expect a PreExplosionBuildup. Compare AGlitchInTheMatrix, OutOfCharacterAlert, ThatsNoMoon, BadVibrations, DroolHello. Contrast CatScare.

----------
!!Examples
* The LaserSight and CrosshairAware tropes are almost invariably used to provide characters with an ImminentDangerClue, even when there is no in-universe rationale for their use, so much so that listing each example here would be redundant. It's the reason that the majority of fictional snipers use laser sights, for example, despite how counterproductive it is. Otherwise the only way to give the characters warning enough to survive a sniper attack would be a missed first shot, which undermines the threat somewhat.

[[foldercontrol]]

[[folder: Film ]]

* In ''Film/TheGodfather Part II'', Michael anticipates his assassination attempt seconds before it happens because the bedroom curtains have been left open.
* In the original ''Film/TotalRecall1990'', Quaid realizes that the Recall doctor's explanation of the trouble he's in is a lie (and that they're about to kill him) from the fact that the doctor is sweating.
* In ''ReturnOfTheJedi'', Wicket senses an unusual scent in the air seconds before a stormtrooper begins shooting at him and Leia.
** When Lando realizes that the Imperials are jamming their sensors, despite the fact that the attack ''should'' be a complete surprise, he immediately concludes that the shield is still up, allowing the fleet to narrowly avoid crashing headlong into it.
* In ''Film/StarTrekIITheWrathOfKhan'', Chekov finds a buckle that says "Botany Bay" and instantly realizes they're on Khan's ship seconds before they're captured.
* In ''Film/DieHard With a Vengeance'', [=McClane=] (BruceWillis) gets on an elevator with some fake cops. Because he was earlier in the film with some real NYPD cops [[LawOfConservationOfDetail who mentioned they always play their badge number in the lottery]], he realizes at the last second that the fake cop next to him has the same badge number as the real cop. This is enough for [=McClane=] to kill them before they kill him.
* In ''Film/TheDebt'', Rachel realizes that the ostensibly unconscious, BoundAndGagged villain in the next room may be escaping when the sound of raindrops hitting pots goes from a three-beat pattern to two (meaning the pot next the the villain's leg has been moved). She goes to check it out, sees the flipped-over pot, starts to creep closer, and promptly gets attacked by the villain, who was hiding just outside the doorway.
* In ''Film/TerminatorSalvation'', the MysteriousWaif appears able to sense when the machines are about to attack. Since she's also a CuteMute, her intuitions tend to be useless unless someone is looking at her at the right moment to notice her panic attack.
* in ''Film/TheWolverine'', at Yashida-sama's funeral, Logan notices one of the monks has a tattoo sticking out his sleeve. In Japan, tattoos pretty much mean "gangster".

[[/folder]]

[[folder: Literature ]]

* In the ''Literature/{{Discworld}}'' novels, hoses and ropes getting tangled for no reason are a sign of Auditors approaching.
* ASongOfIceAndFire: In ''A Clash of Kings'', a character narrowly avoids being murdered by an "ally" on the battlefield in a [[SubvertedTrope subversion]] of TakeMyHand:
-->"It was only at the very last, as their fingers brushed across the gap, that something niggled at him . . . [[spoiler:Ser Mandon]] was holding out his ''left'' hand, why . . ."

[[/folder]]

[[folder: Live Action TV ]]

* On ''Series/BabylonFive,'' during any standoff with a warship, the shooting is usually immediately preceeded by a one of the BridgeBunnies shouting "We're picking up an energy spike!" Usually they aren't ''surprised'' in this case, as starships are [[StealthInSpace usually]] pretty easy to see, but this is the announcement that [[BlastOut the standoff phase of the encounter is over.]]
* In ''{{Series/Crusade}}'', Gideon and Lochley identify that an alien is about to shoot because the alien weapon produces a smell of ozone when it is being charged.
* ''Series/DoctorWho'':
** In [[Recap/DoctorWhoS31E4TheTimeOfAngels "The Time of Angels"]], the [[TempleOfDoom ancient ruins]] they're in were from a culture where the population had two heads, but nobody notices for a while that all the "statues" have only one head each.
** In [[Recap/DoctorWhoS28E4TheGirlInTheFireplace "The Girl in the Fireplace"]], the Doctor realizes something is amiss in a little girl's room when he realizes that the ticking sound he hears cannot originate from the room's one clock, which is broken.
** And in [[Recap/DoctorWho50thASTheDayOfTheDoctor "The Day of the Doctor"]], the UNIT scientific team are standing in the middle of a statue gallery where every installation is covered by a large sheet when they realise the mysterious dust covering the floor is... the remains of the statues.
* In the ''Series/{{Torchwood}}'' serial [[Series/TorchwoodChildrenOfEarth "Children of Earth,"]] a character realizes she and her son are in danger when a neighbourhood dog [[EvilDetectingDog stops barking]].
* ''Series/{{Sherlock}}'': "Why didn't he close the window when he left-- ...oh. Stupid, ''stupid.'' Obviously. He's still here..."
* ''Series/BreakingBad'': A story arc in the first season involves [[{{Protagonist}} Walter]] keeping Krazy 8, a violent drug dealer, locked up in a basement for days while he works up the nerve to kill him. [[spoiler:One day, Walter loses consciousness while bringing Krazy 8 his sandwich, falling and breaking a plate. When he comes to a little while later, he cleans up the mess, goes upstairs, prepares another sandwich, and heads back downstairs. He and Krazy 8 then talk about their lives over beers and actually start to bond despite the situation. Eventually, Walter begs Krazy 8 to convince him that he won't murder Walter's family if he lets him go. Krazy 8 says he won't. This leads to Walter going back upstairs to get the key, relieved beyond measure. He throws something in the garbage and starts going back toward the basement... but a nagging feeling makes him go back to the garbage can, pull out the shards of ceramic from the broken plate, and re-assemble them on the kitchen table. Sure enough, a large, shank-shaped piece is missing, and he realizes that Krazy 8 took it while Walter was unconscious and has been planning on killing him upon release this entire time.]]
* ''{{Warehouse 13}}'': The smell of fudge where there is no fudge indicates [[spoiler:the presence of chameleon bombs]]
* In the ''Series/{{Community}}'' episode [[PaintballEpisode "Modern Warfare,"]] Abed notices a single line of paint trickling down a bathroom wall, steps back, sees the human-shaped bare patches above each urinal, and has time to say "Um, guys?" right before the female characters [[InescapableAmbush spring out of the stalls (and garbage can) behind them]].
* ''Series/GameOfThrones'': In the final scene of "The Rains of Castamere," [[spoiler:Catelyn Stark]] notices three of these just before [[spoiler:the Red Wedding goes down]]. First, someone bars the doors. Second, the musicians [[MusicalSpoiler begin playing a song]] whose key and content are inappropriate for the setting -- [[spoiler:none other than the episode-naming song, a Lannister song which only Catelyn recognizes]]. The final, threat-''confirming'' clue is the reveal that [[spoiler:[[FalseFriend Lord Roose Bolton]]]] is wearing chainmail under his clothes. Sadly, by the time [[spoiler:Catelyn]] pieces all of this together and realizes that [[spoiler:she and her family have been LuredIntoATrap]], [[DownerEnding it is far, far too late]].
* ''Series/AgentsOfSHIELD'':
** In [[Recap/AgentsOfSHIELDS1E2084 "0-8-4",]] Ward's first sign that something is wrong comes when he realizes that the military squad on the Bus still have not touched their drinks even after several hours had passed, implying that there was something they planned to do that they needed to be sober for.
** In [[Recap/AgentsOfSHIELDS1E20NothingPersonal "Nothing Personal",]] while Hill complains about her obvious tails over the phone, she suddenly notices that they've disappeared or have been incapacitated. She immediately ends the phone call.

[[/folder]]

[[folder: Video Games ]]

* In the 2010 reboot of ''MedalOfHonor'', the first mission features a bomb rigged to a cell phone, which the men of [[BadassCrew AFO Neptune]] barely avoid at the last moment when they hear the phone ring.
** Later in the same game, a Ranger squad is preparing to secure a small hut bordering on a potential landing zone for their helicopters. They don't quite make the connection, but they know something's wrong when they hear a phone right just before they are about to kick in the door.[[note]] Fortunately, they were all wearing ballistic body armor, which barely saved them.[[/note]]
* ''VideoGame/TheLegendOfZeldaOcarinaOfTime'': The fight with [[MirrorBoss Dark]] [[EnemyWithout Link]] in the Water Temple starts like this. Link enters a strange room that looks like an endless, ankle-deep expanse of water. In the middle of the room sits a small island with a dead tree. As soon as Link [[EventFlag passes the island]], his reflection is no longer visible in the water...
* ''VideoGame/PokemonMysteryDungeonGatesToInfinity'', your partner notices that the air seems to be growing colder. Unfortunately, [[spoiler: Hydreigon]] is only able to confirm the fact before [[spoiler: [[AnIcePerson Kyurem]]]] ambushes them. [[spoiler: [[LiterallyShatteredLives It doesn't end well for the latter]] [[NoHoldsBarredBeatdown (Or the hero for that matter)]].]]

[[/folder]]

[[folder: Webcomics ]]

* In the comic ''HomeStuck'', the sound of a [[HellIsThatNoise horn honking]] is usually a bad sign.