When muscular jock Robbie Dobkins captures Betty and Veronica's attention, Reggie starts eying Dilton's latest invention: a muscle-enhancer that works in seconds. Ignoring Dilton's protests that it's not ready, Reggie sneaks into the lab to steal it and splashes himself and Archie with the formula. However, it turns out Dilton's concern was justified — on humans, the "muscle enhancer" induces invisibility and gradually causes the user to fade from existence. Can Archie catch Reggie before it's too late?
This episode includes examples of the following tropes:
- Angry Collar Grab: Robbie grabs Reggie after the latter pantses him in front of the student body.
- Dramatic Drop: The invisible Archie dashing into the room nearly causes Dilton to drop one of his vials twice. After barely catching the antidote, Dilton snaps that Archie has got to stop startling him that way.
- Fading Away: While it's not visible, Dilton says that Archie and Reggie will fade out of existence in a few hours just like they faded from sight. Unfortunately, Reggie doesn't listen to Archie's warning about it.
- "I Can't Look!" Gesture: When Robbie grabs Reggie after he pantses him, Veronica and Betty both shut their eyes. The sound of Reggie getting beaten up comes from offscreen.
- Invisible Main Character: Archie and Reggie become invisible due to the effects from one of Dilton's potions. Archie spends the time trying to get back to normal before the effects become lethal while Reggie, unaware of the possible danger, went into Invisible Jerkass mode.
- Laser-Guided Karma: Reggie spends his time being invisible tormenting Miss Grundy in front of the class and attempting to humiliate Robbie at the sports tournament. When Dilton and Archie undo his invisibility, he doesn't immediately realize it and pulls one last prank. Robbie beats him up offscreen.
- Pants-Pulling Prank: In a final attempt to embarrass Robbie, Reggie pulls down his pants in front of the audience. This prank actually works. However, Reggie performs it oblivious to his becoming visible again. Able to see his tormentor, Robbie beats the stuffing out of him in retaliation.
- Properly Paranoid: Dilton refuses to let Reggie have the muscle enhancer, saying that it hasn't undergone human testing and he has no idea how it would affect a person. It turns out he was right.
- Stock Footage: A scene of Dilton nearly dropping a vial gets used twice.
- Tied-Together-Shoelace Trip: While invisible, Reggie ties together Robbie's shoelaces to embarrass him at the track meet. Unfortunately for Reggie, Robbie is strong enough to snap the knotted section off without noticing.
- The Unfettered: Reggie enjoys his invisibility, citing his earlier opinion that having no one watching you means you can do anything. Luckily, he only does things like pull pranks.
- Visible Invisibility: Averted. Reggie and Archie are completely invisible under the influence of the potion. The viewer can only tell where they are if they interact with something visible.
