When the gang heads home for Valentines, they learn of a series of disappearances on Lovers Lane. What's more, they're the lead suspects!
This episode includes examples of the following tropes:
- Adaptational Villainy / As Himself: J.C. Chasez turns out to have been the culprit of the episode, willing to have the Scooby Gang sent to prison due to Rachel talking non-stop about Shaggy.
- Bait-and-Switch: When JC's motive is revealed, it seems like Rachel is appalled that he went to the lengths he did... before admitting she thought it was sweet of him.
- Clear My Name: After the Scooby Gang is falsely imprisoned, Daphne and Velma talk the police officer into letting them go as to prove their innocence. Given how this happens in the last act of the episode, you can already guess the punchline.
- Faked Kidnapping: As it turns out, no one was actually taken from Lovers Lane. JC was hiding them at his cabin; when the Scooby Gang shows up at the end of the episode, they're in the middle of a party.
- Green-Eyed Monster: JC's motive: He was tired of how Rachel kept talking about her ex Shaggy, so he decided to frame the Scooby Gang for kidnapping and ruin Shaggy's reputation.
- Hypocritical Humor: Daphne and Velma are shown wearing orange prison jumpsuits when Officer McBride interrogates them. Daphne pleads that she doesn't want to go to jail because she doesn't want to wear the same clothes every day, when, like many cartoons, the main cast of Scooby-Doo always wear the same clothes.
- Ink-Suit Actor: In "A Scooby-Doo Valentine", the Hollywood extras who disguised themselves as the human members of the gang are unmasked to be caricatures of their voice actors — Frank Welker (Fred), Grey DeLisle (Daphne), Casey Kasem (Shaggy), and Mindy Cohn (Velma), with former *NSYNC member J.C. Chasez disguised as Scooby-Doo.
- "Meet the Celebrity" Contest: Velma gushes without thinking that she's entered the "Win a Date with J.C. Chavez" contest hundreds of times. When everyone looks at her, she tries to pass it off as being a research project.
- Mythology Gag: Daphne laments that the fact that she was impersonated by an extra (who, ironically, resembled her voice actor, Grey DeLisle), saying, "What, Sarah Michelle Gellar wasn't available?". Sarah Michelle Gellar played Daphne in the Live-Action Adaptation of the franchise.
- Red Eyes, Take Warning: The fake Scooby Gang all have red eyes.
- Tally Marks on the Prison Wall: When the gang gets arrested, Fred is seen using a knife to carve five tally marks into the wall of his cell, and stating that they've been locked up for five hours.
- Tricked into Signing: As part of their plan, the culprit forged a confession letter from the gang using signatures they tricked them into giving.
