Basic Trope: The hero discovers they've been dealing with an imposter when their real friend/Love Interest reveals they've been somewhere else the whole time.
- Straight: Bob goes exploring in a dark tunnel in Alice's house. Partway through the trek, he hears Alice say she got worried and came to find him. The two manage to get to a door... only for Alice to open it from the other side and ask where Bob has been all this time.
- Exaggerated: Bob and his entire town go exploring... And soon afterwards, he meets everyone else at the other side and asked where he was.
- Downplayed: Bob only hears Alice's voice from somewhere else.
- Justified: The imposter is a shapeshifting Emotion Eater that wanted to replace Alice.
- Inverted: Bob goes exploring in a dark tunnel. Partway through, he hears Alice say she got worried and came to find him. He gets suspicious and keeps interrogating her, trying to get her to confess to being an imposter...only for a monster to spring on them midway through the interrogation.
- Subverted: Bob goes exploring in a dark tunnel in Alice's house and is joined by Alice, who says she got worried and came to find him. Then Alice opens a door onto the tunnel from the outside and asks where Bob has been all this time...but after a Spot the Imposter test, it's revealed that the Alice from outside the tunnel was a shapeshifter.
- Double Subverted: Alice and Bob then fall asleep on the couch...only for Bob to awaken to Alice asking when he came to visit her. Turning to the other "Alice", he sees a Nightmare Face.
- Parodied: ???
- Zigzagged: ???
- Averted: ???
- Enforced: ???
- Lampshaded: ???
- Invoked:
- The shapeshifter sets up Bob to think she's Alice and then realize she isn't in order to scare him.
- Alice and her identical twin sister Brittany love playing this prank.
- Exploited: ???
- Defied: Bob and Alice have a Trust Password specifically for cases like this.
- Conversed: ???
- Discussed: ???
- Played for Drama: When both Alices see each other, they both scream and insist to Bob that they are the real Alice and the other is an imposter. The difficult part is that neither of them is intentionally lying — the "fake" Alice has no memory of not being Alice and truly believes she's the real one, and when definitive proof is found establishing which one is the real one the other one is devastated.
Wait a minute...If Fright Beside Them is on the main page, then what have I been reading?
