A protagonist walks into a top-secret workplace, and no one reacts. We get a quick montage of people doing technical-looking things and glimpses of weird stuff while the spectator walks around in silence, goggling at it all, and still no one reacts.
Only when the audience has had a complete lab tour does anyone notice the visitor. Then, the other characters' response will indicate whether it is a Mad Scientist Laboratory or a legit one.
This is most common in the Premiere of a Speculative Fiction series. Maybe a Naïve Newcomer discovers that their new office is considerably stranger than they expected. Maybe some ordinary person accidentally stumbles onto a secret lab belonging to the Big Bad or to an Ancient Tradition, and swiftly stops being ordinary. Either way, the audience gets an introduction to the show's favoured brand of Phlebotinum. Extra points if at some point the intruder is shown distorted on the other side of some sciencey-looking glassware.
An Unguided Lab Tour can also happen any time a new villain or secret organisation is being introduced to the show. Often an occasion for Exact Eavesdropping, for when the characters overhear crucial information. If the character is trying to sneak into the top-secret place, then they will probably grab a Clipboard of Authority to look like a lab worker or pull a Bavarian Fire Drill.
Related to Swiss-Cheese Security, when a facility's security detail is so faulty that it's like it wasn't there in the first place.
Anime & Manga
- Black Cat: Rinslet sneaks into Tornero's lab to steal information and discovers human experiments that look like chimeras.
Films — Animation
- Miniforce: New Heroes Rise: The Miniforce tries but fails to sneak into a lab to take the Control Cube so that it doesn't fall into the wrong hands.
- Pokémon: The First Movie: Team Rocket sneaks onto a secret island and discovers the cloning lab that Mewtwo built there.
Films — Live-Action
- James Bond: Agent 007 does this on occasion, though most of the time he's impersonating someone who has a reason to be there.
- Being John Malkovich: Pretty much how the portal to John Malkovich's psyche is discovered.
- Austin Powers: International Man of Mystery: This is part of how Austin and Vanessa are able to get into a compound.
- Harry Potter and the Order of the Phoenix: The Ministry of Magic's Department of Mysteries is where the mysteries of magic are researched by specialists known as Unspeakables. Upon arriving there, Harry and five other D.A. members find themselves in a circular entrance room with twelve, black, identical doors. It's a downplayed case because the heroes only enter three of the doors because they are in a race against time. The first door leads to a room full of eerie (and later, aggressive) disembodied brains. The second opens to an atrium with the Veil (a life-death limbo of sorts) in its center. The third doesn't open, so they try a fourth and it leads them to a room littered with time-turners and clocks. Harry recognizes their glittering lights from his dreams, so they don't return to the Entrance Room but continue forward. They get to the room they are looking for, the Hall of Prophecies and it's there that they are finally noticed. This makes it an Invoked Trope too because the Death Eaters put an alarm in one of the orbs in the hopes of Harry successfully evading the Ministry personnel and security until they have him exactly where they want him.
- Jake 2.0: In the pilot episode, Jake's status as tech support guy at the National Security Agency gets him into both the main situation room (while a major op is going down) and the super top-secret lab where nanobots are being created. In both cases, he spends several minutes gawping at the urgent, top-secret goings on before remembering that he's there to fix some Bridge Bunny's hard drive.
- The Professionals: "Involvement" features Doyle's girlfriend wandering into the top-secret security organization CI5 and eavesdropping on an interrogation.
- "Everything Changes": Subverted when Gwen bluffs her way into the Torchwood base. All the other characters did notice her, they were just pretending to not see her until they couldn't keep it up anymore and burst out laughing.
- "Random Shoes": Justified when Eugene stumbles into the Torchwood lab. They can't notice him because he's a ghost.
- The X-Files: This comes up a couple of times, regarding academic or government labs doing secret things.
- Fallout: New Vegas: As long as you're not too badly regarded by the NCR, you can easily sneak into Hoover Dam's facilities, including the turbine chambers, the armory, the offices, and the barracks without anyone even asking who you are or making you relinquish your weapons. If you so wanted, you could probably plant a few bombs and cripple the region (although there's no quest to do so).
- Perfect Dark: Joanna's missions sometimes require her to sneak into and investigate several high-tech, top-secret labs such as dataDyne Central (her institution's rival), Area 51 (Government facility, hints about the existence of aliens), and the Pelagic II (Government ship overtaken by dataDyne). Justified because she's a secret agent —it's literally her job to go unnoticed.
- Dexter's Laboratory: The Title Sequence starts with Dee Dee entering her little brother's laboratory through a tube slide covered by the carpet in his bedroom. She passes through a "Danger!" warning and a "Dee Dee forbidden" sign and several tech devices —from antennae to robots, screens with diagrams, and lasers. She's not discovered until she steals Dexter's remote control for his latest invention: the show's title.
- Johnny Test: In many episodes, Johnny is in need of a quick solution to the trouble he's gotten into but either his sisters aren't home or they can't/won't help him —he's been a nuisance or their experiment of the week is too unstable still. Behaving with the recklessness that characterizes him, Johnny often decides to screw it and forces his entrance to the lab. As he's searching for whatever is it that he was denied before (or that looks interesting enough), the viewers get a glimpse of the current state of the sisters' laboratory. On some occasions, Jonnhy triggers a security mechanism while he is grabbing (or already has) the experiment he wants.
- Winx Club: In "Mission at Cloud Tower", the Winx sneak into Cloud Tower to retrieve Stella's rings from the Trix's bedroom. After finding it, they hear the Trix returning and rush to escape, getting themselves into the school's top-secret vault: the Crypt of the Magic Archive. When they enter, the camera pans to show several bookcases (which contain biographies of every notable fairy and witch to have ever existed), a statue holding an axe, and a planet globe. A curious Bloom picks up a book whose contents are unknown, therefore alerting Headmistress Griffin of intruders in the vault. The other girls follow suit until they all find a book about Bloom —it turns out to be a trap set up remotely by Griffin.