In the first part of the finale, the gang goes to Professor H.P. Hatecraft for help figuring out what the mysterious treasure they got from the Darrow Mansion is, only to be hunted by the mysterious assassin Obliteratrix who plans on destroying Mystery Inc.
The episode provides examples of:
- Batman Gambit: Mr. E. had Alice May hunt the gang as Obliteratrix to draw Pericles out of the woodwork.
- Big, Stupid Doodoo-Head: Regina Wentworth directly calls Hatecraft "H.P Buttcraft", and earlier on made childish remarks about him being old. She seems genuinely proud of herself for those insults, too.
- Blatant Lies: Alice May states that she was given weapons by Quest Laboratories, a subsidiary of Destroido. However, the actual flashback scene makes it clear that she stole them instead.
- Book Ends: The episode begins and ends with The Freak.
- Butt-Monkey: Professor H.P. Hatecraft is being forced to write a teen vampire romance novel to keep up with a younger author who constantly insults him... then he gets fired.
- Call-Back:
- Alice May had gotten out of police custody at the end of her debut episode.
- The original Mystery Incorporated and an unidentified man are analyzing a map, which appears to be the same map that Mayor Jones was looking at back in "Menace of the Manticore". The unidentified man turns out in the next episode to be his younger self.
- The Cameo: Alice May states that she got her equipment from Quest Laboratories, and the accompanying flashback shows the Quest team themselves for a bit.
- Early-Bird Cameo: The man whose back is turned away from the camera in the flashback of the old Mystery Inc. is a young Fred Jones, Sr.
- The Faceless: The man warning the original Mystery Incorporated in Cassidy's flashback is only seen from the back.
- Foreshadowing: In Cassidy's flashback, we see that a black-haired man with glasses, a suit, and a familiar-looking hairstyle is telling the original Mystery Inc. about the Curse of Crystal Cove. This man conveniently is facing away from the camera. It turns out he's a young Fred Jones, Sr., which we find out in the next episode.
- Hammerspace: Lampshaded by Shaggy about Obliteratrix, especially when she pulls a giant bow and arrow rocket launcher after doing a combat roll.Shaggy: Like, where does she keep getting these weapons? That outfit has no pockets!
- Internal Reveal: At the end of the episode, Angel confesses to the gang that she's actually Cassidy Williams.
- Jerkass: Regina Wentworth, H. P. Hatecraft's substitute partner while Harlan Ellison is away. She upstages him with her teen vampire romance novels and deliberately pins the blame on him for the explosions at the school, to get the Dean to fire him.
- Leaning on the Fourth Wall: Shaggy tells Hatecraft that he and the rest of the gang have "been teenagers forever", a nod to the fact that the Mystery Inc. gang has basically stayed the same age throughout the franchise.
- Mistaken for Undead: Shaggy and Scooby frequently refer to Obliteratrix as a "ghost" or "undead", but she doesn't actually display traits of either.
- Monster of the Week: Obliteratrix, a futuristic assassin intending to destroy Mystery Inc. by any means necessary.
- Mysterious Mercenary Pursuer: Obliteratrix.
- No Celebrities Were Harmed: Regina Wentworth, author of the “Dusk” series, is a parody of real life author Stephenie Meyer and Twilight series.
- Police Are Useless: Sheriff Stone apparently hadn't noticed that Alice May escaped from prison. When informed of this, he flat-out refuses to believe he'd make a mistake like that.
- The Reveal: A monster known as the Freak terrorized the original Mystery Incorporated into disbanding and leaving town twenty years ago, as the curse threatened to hurt their families.
- Throw the Dog a Bone: Towards the end of the episode, the dean comes back to reveal that the song Char-Gar-Gothacon, based on his book, is a massive hit in Japan, while Regina Wentworth’s Dusk series fell out of fashion. So Hatecraft gets his job back for bringing revenue and prestige to Darrow University.
- Totally Radical: Hatecraft's attempt to write a teen vampire novel is this, combined with his typical writing style.
- The Freak: The curse begun, but soon they'll see, the buried truth will end with me.
