This is when the entire Plot of a work depends on someone being left out of the loop. It may be that the person or group keeping the secret is holding the Idiot Ball, or is Properly Paranoid, or maybe they simply Cannot Spit It Out. Whatever the reason, they have kept a key player from knowing something crucial, and it is that lack of knowledge that enables the plot to happen. Otherwise, they could simply Just Eat Gilligan.
May result in Poor Communication Kills.
- The Con — "Wait, you're not a Nigerian Prince who needs help hiding his fortune?"
- Bruce Wayne Held Hostage — "You mean our hostage is actually The Hero we took hostages to lure in?"
- Locked Out of the Loop — "You all knew this?" "Yes, but there's a reason we didn't tell you."
- Loves My Alter Ego — "You mean the guy I love and the guy with an unrequited crush on me are the same man?"
- Masquerade — "Dude, they're really vampires?"
- Almost every mystery depends on someone not knowing who the culprit is. Once that knowledge is revealed, the story ends, unless the plot is actually about gathering evidence.
- Law & Order: Criminal Intent gets around this... by switching the this from 'whodunnit' to 'whydunnit'.
- Any character with a Secret Identity is likely to have a few stories of this nature.
- Pretty much every undercover cop story runs on this. If the criminals knew from the outset that the new guy in their ranks was a cop out to bust them all, they would be dead in short order.
- The plot in Nosflutteratu kicks off when Twilight learns what everypony else in Ponyville already knows-that Fluttershy is a vampire.
- In The Way, Way Back, a lot of things would've been easier if Duncan had just told his mom he'd gotten a job. But then the plot would've had to be quite different...
- A minor plot point in Akata Witch was that Sunny was the only one in the group whose parents weren't magical and didn't know that she was taking lessons to improve her magic.
- In the Fearless books, the plot was frequently driven by the fact that Gaia was either keeping a secret from someone or having one kept from her.
- In Lucifer (2016), the Deuteragonist Chloe always disregards Lucifer's Cassandra Truth that he's the Lucifer Morningstar, first among angels, Prince of Hell, and not just a quirky, delusional nightclub owner. She realizes the truth in the Season 3 finale, just in time for the show to be canceled.
- In Pretty Little Liars, "A"'s identity is the main mystery of the entire show.
- The Secret World of Alex Mack would likely have been a much different show if Alex had told her parents about the accident.