During an investigation, Fred encounters a mirror that pulls him in, leaving a fake Fred in his place. Meanwhile, the real Fred tries to find out why the town is deserted and why the only human around is an old Daphne.
The episode provides examples of:
- Bad Future: This is what the ruined town is set up to be...except it isn't.
- The Bad Guy Wins: Professor Pericles successfully gets the Planispheric disc.
- Berserk Button: Scooby is outraged over Fake!Fred saying there's no difference between a Scooby Snack and any other dog treat.
- Big "NO!": Fred in the supposed Bad Future when he thinks something horrible happened to Daphne.
- Bluff the Eavesdropper: Fred reveals he was doing this the whole time he was with Old!Daphne. After figuring out she was a fake trying to learn where he hid the Planispheric disc, he knew someone was impersonating him and listening in to hear whatever location he'd name. He proceeded to fake not remembering where he hid the disc and picked specific locations that would (as Velma later demonstrates) spell out "Fake Fred" when written in a list.
- Boring Yet Practical: How Professor Pericles finally gets the Planispheric disc. He simply has Daphne held hostage and demands the disc in exchange for her release.
- Calling the Old Man Out: Fred denounces Brad as a heartless criminal.Fred: I don't know what you're thinking you're doing. You're supposed to be my father, but how could you try to impersonate me when you know absolutely nothing about me?
- Character Catchphrase: As Fred says, “Daphne says ‘Jeepers’, Velma says ‘Jinkies’. No-one says ‘Jeepees’.
- Dagwood Sandwich: Shaggy and Scooby try to eat these, but “Fred” refuses to let them eat in the van.
- Dem Bones: The skeletons come to life at midnight
- Doppelgänger: The Fake!Fred (Brad) and Old!Daphne (Judy).
- Empty Piles of Clothing: Shaggy, Scooby and Velma appear to have been vaporized.
- Faked Rip Van Winkle: What Fred's parents try to pull on him but he figures it out fast.
- Finishing Each Other's Sentences: Daphne to Fred's, that she interprets as having a special connection. And then Scooby, Shaggy and Velma finish Fred's next sentence. Either they are all soulmates, or Fred is just that predictable.
- Genre Blindness: Defied. Brad explains that they went with plastic surgery for this scheme because the gang would naturally see through a simple mask too quickly.
- Idiot Ball: After realizing that Old!Daphne is a fake trying to get him to reveal the location of the Planispheric Disk, deducing that another imposter is pretending to be him with the rest of the gang, and skillfully leading them on a wild goose chase to red herring locations that spell out a secret warning message to the gang, Fred decides to... head straight to the disk's real hiding spot. Instead of, well, literally anywhere else.
- Insane Troll Logic: Invoked by Fred:Fred: Convincing me I had to save my friends from a post-apocalyptic future was the most obvious way to get me to tell you where I hid it. It's exactly what I would have done!
- Magic Plastic Surgery: Brad and Judy get surgery to look exactly like Fred and an old Daphne but it's not gonna be reversed.
- The Mole: Old!Daphne
- Obfuscating Stupidity: Fred faked not remembering where he hid the Planispheric disc and kept dragging Old!Daphne to the wrong locations. Deducing he was being monitored by Fake!Fred, he used it as an opportunity to send a covert message to the rest of the gang, which Velma ultimately cracks.
- Not a Mask: When Fred returns to the real world after learning that the post apocalyptic future he was sent to was just a film set, he tries to unmask both Fake!Fred and Old!Daphne only to realize that it's Brad Chiles and Judy Reeves who have gotten plastic surgery.
- Only Known by Their Nickname: After Fake!Fred calls Shaggy "Norbert" instead, Velma says it's "Norville" and adds that no one calls him that, anyway.
- Out-of-Character Alert: Doppelgänger or no they suck at acting as they should. Old!Daphne is more convincing but still botches the real Daphne's catchphrase.
- Parental Neglect: Brad makes a host of basic mistakes while impersonating Fred, including routine habits and details about Fred's friends. Fred scoffs at how a father who clearly knows nothing about him tried pretending to be him.
- Perfect Disguise, Terrible Acting: Brad and Judy use Surgical Impersonation to make themselves look like Fred and an older version of Daphne respectively. The disguises are convincing, but their blatantly out-of-character statements and actions tip off everyone that something's amiss.
- Sadistic Choice: Pericles issues an ultimatum: The Disc or Daphne.
- Shout-Out: The gang drives past a building with the sign "Iwao's Place", a reference to Iwao Takamoto, the character designer for the original Scooby-Doo series.
- Smart Ball: Fred spotted the imposter immediately, realized he was being monitored, and worked out a way to tip off the gang to what was going on. He also figured out who his fake counterpart was before anyone else did.
- Something Only They Would Say: How Daphne can tell the two Freds apart. The real one puts her after traps and mysteries and stumbles over his words compared to the fake who's very suave around her.
- Spot the Imposter:
- Fred reveals he saw through the whole "dark future" thing from the very beginning as Fake!Daphne said "Jeepies," a baffling word. Knowing that, Fred was able to check out one of the "zombie skeletons" and see the labeling of it being a fake.
- Daphne is able to pick out the real Fred from the fake by knowing that the real Fred Cannot Spit It Out when talking about his feelings for her.
- Surgical Impersonation: That's no mask meaning that both Brad and Judy are now stuck like that..
- Tempting Fate: Horrified over seeing Scooby, Shaggy, and Velma's Empty Piles of Clothing, Fred asks how it could get any worse. Daphne's scarf then blows into view.
- Two Lines, No Waiting: As the description shows.
- Wham Episode: Professor Pericles gets the Planispheric disc and reveals his plan to release the most evil Annunaki.
- Wham Line: Pericles: "I'm coming for you, master. (places Planspheric Disc in its keyhole) I'm coming to set you free."
- Wham Shot: In The Teaser, Fred looks into the strange mirror and adjusts his ascot. He steps away, but the "reflection" is still standing there.
- Pericles: I'm coming for you, master. I'm coming to set you free.
