Hey, Wait!

Our heroine has talked her way past a security checkpoint on her way to uncovering the government's dirty secrets... almost. Just as she's about to round the corner, though, the guard cries, "Hey, wait!" Our hearts pound—she's been caught!

But no—the guard just wanted to tell her she left her keys on his desk. Or she's to report to Drill Sergeant Nasty for a potato-peeling Mini Game. Or it's past time for her shift guarding the Easily Rescued Prisoner's cell. A Cat Scare for The Infiltration, if you will.

If this occurs right before the Act Break, that's a Pseudo Crisis.

Examples of Hey, Wait! include:

Anime and Manga

Tragically subverted in Cyborg 009: In Albert's backstory, he was trying to pass the Berlin Wall. Everything checks out, but as he starts driving through, the guard realizes he still has Albert's wallet and calls out "Hey, wait!" Albert panics and floors it; it didn't end well.
Early on in Yu-Gi-Oh!, Honda and Anzu stow away on the ship carrying Yugi and Jonouchi to Duelist Kingdom, where official rules state that those who have no Star Chips are to be ejected from the island. On the way off the boat, Honda walks stiffly past the guards, who notice him... only to tell him to loosen up a bit. The non-duelists' presence on the island is not questioned at any point, even through the several periods in which they are in the presence of tournament officials who are throwing people off the island for having no Star Chips.
In Digimon Adventure, this is played with. Wizardmon successfully lies that he is going to relieve Bakemon, and talks him into handing over the key to Myotismon's coffin.
An episode of One Piece has Luffy, Carrot, Nami, and Chopper break into a Marine base, eating in their commissary and not showing much concern for stealth. Nami seems to be noticed first by one of the chefs - because she thinks Nami is way too thin and needs to eat more.
- Same episode, she's terrified when Zappa stops her and does know who she is, but he's far more interested in courting her than arresting her. Which unfortunately, given her reaction, is worse.

Comic Books

In the Marvel Comics Star Wars story "The Stenax Shuffle!", Han and the others are trying to sneak past an Imperial Governor. They're almost out of range when he shouts at them to halt. Turns out he was yelling at Han for dropping his shovel.

Fan Works

Yu-Gi-Oh!: The Abridged Series parodies the previously mention stowaway scene and this trope in general, particularly in the fourth episode:

Tristan: I sure hope nobody notices we're trespassing.
Guard: Hey you...
Tristan (thinking): The irony.
Guard: Quit drawing attention to yourself. You barely qualify as a sidekick.

Film

Monsters, Inc..: Sulley has just snuck a human child into the scare factory, which is currently under thorough inspection for any sign of human children. Suddenly, a group of Child Detection Agents run up to him—Hey, Wait!, that's the guy! Can we have your autograph?
In Toy Story 3, when Barbie goes to the Bookworm wearing Ken's spacesuit to get back Buzz's instruction manual, he notices her high heels when she walks away... then just rolls his eyes and sighs.
In the third Austin Powers:

Henchman: You didn't really think you'd get away with this, did you?
Austin: I did, actually, yes.
Henchman: It's time for your physical.

Indiana Jones
- In Raiders of the Lost Ark, Indy gets stopped by a sergeant and told off for having an ill-fitting guard outfit. Indy, being Indy, gets a much better fitting uniform from the sergeant. What makes it especially funny is that this is itself a subversion of a trope—Indy's first uniform didn't fit because he got it from a random guy and there's no reason a random guy would be the same size as the hero, decades of film to the contrary.
- In Indiana Jones and the Last Crusade, Indy comes face-to-face with Der Führer himself. We are certain something bad is about to happen to our hero, or the book he's carrying (given that this is at a book burning and the book has Hebrew in it)... but no, instead he gets Hitler's (incorrect) autograph.
The Fugitive: "Your fly is down."
Ocean's Eleven (the one with George Clooney): "You forgot your portable TV."
Slight twist on this in the first Mission: Impossible film. The character of Luther leaves his seat on the TGV and a train attendant hey waits him to return his cell phone. The problem is, the cell phone was rigged up to block a transmission of the Mac Guffin information, and by taking it away, Luther risked letting the info into the open.
The Red Violin: When Samuel L. Jackson's character, Moritz, enters the auction house, he tells the valet, "Don't let me forget this" (his overcoat). Later, just after he leaves the auction house, crossing the street, having stolen the Red Violin, someone calls out to him, and, in shock, he almost gets hit by a car, but it's just the valet—he forgot his overcoat.
Iron Man features an extended scene that is one big Hey Wait! between Obadiah Stane (the villain) and Pepper Potts (the side kick) after she has downloaded the files involving his conspiracy. Unusually for this trope, though, Stane does realize what happened... just after Potts gets out of his reach, and starts talking with the guy from S.H.I.E.L.D.
Happens in Psycho, as Marion is pulling away from California Charlie's (with the scary sunglasses-wearing cop watching) in the car she's just bought. (She forgot to get her suitcase from her old car.)
In The Grifters, the male protagonist is stopped by a cop right after getting sucker-punched in a bar when one of his cons was exposed. The cop had seen him staggering, and thought he was drunk or ill and wanted to make sure if he was alright.
Inverted in Equilibrium: the sweepers' commander demanded Preston's ID, which was in the trunk of his car (with a puppy, which he was hiding), in a hostile tone. The scene escalates the sense of an impending shootout, just when the commander recognizes Preston, makes an excuse and turns around. And then it ends in a shootout anyway.

Literature

Early in Layer Cake, the protagonist is stopped by a police officer under very unfortunate circumstances, this being a rare occassion in which he was carrying around his "business supplies" (tools for making cocaine ready to sell). Luckily for him, the officer just wanted to know if he had seen a prowler sighted in the area.
Inverted in Medalon, in which one of the heroes calls the guards back to make another innocent remark to make their situation seem more plausible.

Live-Action TV

In an episode of Angel, Fred has to dress as a showgirl, complete with green body paint, to get past security in order to rescue Lorne the empath demon from captivity as a Vegas act. She manages to evade uncomfortably lascivious conversation with the guards, and slips by, only to be stopped...because she missed a spot of paint on the back of her neck, and really ought to fix it before she goes out on stage.
In Merlin 1X04, when Gwen goes to deliver the meal to the jailed Arthur to find out if he successfully retrieved the Mortius Flower, this occurs just as she's leaving, with the flower on her tray, but it turns out that the guard just wanted a bite from the food Arthur rejected.
In Robin Hood Djaq disguises herself as a serving girl and walks past Guy of Gisborne. Hey, Wait!... he just wants to remind her to keep the Sheriff's cup full.
In the Buffy the Vampire Slayer episode, "The Bad Girls", Buffy and Faith are arrested after breaking in and robbing a military supply store (Faith's idea) and then escape by forcing the police car to crash (again, completely Faith's idea). When the justifiably worried Buffy gets home (it is now morning) she meets her mother in the kitchen, who suddely says, "Admit it!" Has she been caught? Then her mother adds, "Some days don't you wake up and want to say 'to Hell with the diet'?" And then she offers to make Buffy waffles.

Video Games

In Fallout 2, if you infiltrate a base in old-fashioned power armor, a sergeant notices, and then sends you to get some spangly new power armor from the Armory. Note that he's absolutely furious, because he naturally assumes that you've lost it and are trying to play off like you never had any. Sergeant Dornan is probably the best character in the game simply for the dialogue you get if you talk to him while not wearing the Mark II Power Armor. Even better: he stops you for wearing the second-best armor in the game to order you to go equip the best armor.
In Final Fantasy VI, the guard in Celes' room seems to wake up when Locke rescues her. He's actually just sleepwalking.
In Final Fantasy VII, this happens when Cloud sneaks into Junon, and he has to go march in a parade.
In Final Fantasy IX, Steiner is trying to smuggle Princess Garnet across the border to Treno, by posing as a travelling labourer while Garnet hides in a sack of pickles he's carrying. As he's about to walk out of the other side of the border control point, a guard yells after him to stop... because all the necessary paperwork has been completed and Steiner's new passport is ready.
In Final Fantasy VIII, while infiltrating a missile base, the first guard you encounter inside the facility will stop you and, depending on the option you chose beforehand, will warn you not to run on the catwalks, compliment you on your marching formation, or chastise you for walking strangely (when you're very obviously trying to hide your faces from him).
At the beginning of Fahrenheit, the main character has just killed a man in the bathroom of a diner. If you try to leave through the front door, the cashier calls for you to stop. You can either stop and listen, or bolt out the door anyways; in either case, she was only trying to remind you to pay your bill.

Web Comics

Used in this strip of The Order of the Stick. Roy, disguised as (and gender-changed into) a woman thinks s/he's been caught by "Kaboom" Redaxe... but the perverted dwarf just want to give "her" his room number.

Western Animation

Happens quite a bit on Avatar: The Last Airbender.
- For example, when entering Omashu with Aang dressed as an old man, the guard lets them through, pauses, then makes Sokka carry the old man's pack.
- And again, when trying to lay low in the Fire Nation, the guards notice he's acting highly suspicious, and force him to attend the school whose uniform he stole off a clothesline.
Variation in American Dad. While Stan is away, Steve and his friends go into his study and accidentally flies and crashes a Predator drone. When Stan returns, he calls Steve to the study, noting that the Predator computer shifted while he was gone (and repeatedly, just to build the tension). Then he announces he is wrong and it is where Steve had left it, and tells him to forget about it. Double Subverted when moments later Stan can't connect and finds it missing from its hangar.
Happens in J.G. Quintel's student animation "2 in the AM PM" when a cop visits the gas station while Quinetl's and Sam Marin's characters are hallucinating on LSD.
In the Adventure Time episode "Death in Bloom", as Finn and Jake are sneaking around in the Land of the Dead, a skeleton yells Halt! He was talking to his friend, Halt.
Bruce Wayne/Batman has been on the other end of this at least twice in Batman: The Animated Series.
- In one episode, Harley Quinn meets Bruce Wayne and covers the top half of his face, saying she recognizes that chin. Bruce thinks he's been found out as Batman, but it turns out she was actually referring to Bruce Wayne.
- In "Joker's Wild", The Joker - who is posing as a blackjack dealer in a Joker-themed casino where all the dealers are dressed like him - seems to recognize Bruce from somewhere. But he also only recognizes him as Bruce Wayne.
In the pilot episode of The Owl House, Lutz flees from Eda, thinking she's some Wicked Witch who wants to eat her; in truth, Eda (who makes a living selling junk stolen from Earth as "human artifacts") sees Lutz as a potential customer - much like she sees anyone she meets for the first time.