The gang investigates a missing soccer ball in the desert on Mount Diabla, which the locals claim to be haunted by the ghastly Dark Lilith! However, the team gets more than they bargained for when they come across another clue about the Planetspheric Disk.
The episode provides examples of:
- Apocalyptic Log: The Ship's Manifest.
- Batman Gambit: Marcie's plan for how to get the piece of the disk. She couldn't get past the traps on the ship, so she instead tricked two other students into going to the mountain and appeared to them as a monster with the knowledge that it would lure the team there and Fred would do it for her.
- Dramatic Drop: A teacup.
- Fanservice: Dark Lilith's costume. Her loincloth leaves very little to the imagination.
- Foreshadowing: Even without the Previously on… segment suggesting she'd be in the episode, there's a couple of hints that Dark Lilith is Marcy.
- When confronting the gang, Ugly Jimmy, and Boron in the cave, she specifically uses the term "delete" as befitting her technological expertise.
- When she flies off after Ugly Jimmy fell, Velma notes a familiar scent in the air, reflective of Marcy's distinguishing "hotdog water" smell.
- She was specifically following the gang to retrieve the piece of the Planispheric Disk, something that only someone who already knew about them would want like Mr. E, who Marcy was still working for.
- Gory Discretion Shot: The Captain describes how he and his crew were driven to do "horrible things". In between the line we get a shot of fleeing women and children before bringing down his sword.
- Informed Deformity: Ugly Jimmy is considered hideously disfigured by the hillbillies, but Daphne realises how conventionally attractive he really is… until he ends up actually disfigured after falling off a mountain.
- Made of Explodium: Scorpion Wells City Hall. Justified as its used to stockpile propane and other explosives.
- Makes Just as Much Sense in Context: Boron's entire inclusion is riddled with this. Introduced as a random explorer with seeming memory issues, she shows up treating the lucky soccer ball like it was alive, guides the gang to the ship at the top of the mountain, then vanishes without a trace when Daphne goes to ask her something. Who she really was and what she was even doing on that mountain outside of "boron mining" is never explained.
- Mayincatec: The natives that the Captain's crew happened on and the Planispheric Disk are this.
- Monster of the Week: The Dark Lilith, a female demon who lives on Mount Diabla and terrifies visitors.
- My God, What Have I Done?: The Spanish captain's reaction after realizing just how brutal he and his crew have become in their lust for treasure.
- Mythology Gag: Scorpion Wells is the episode's main setting. Scorpion Ridge was the main setting in Scooby-Doo and the Alien Invaders.
- Only Friend: Marcie's motivation for letting Velma have the piece of the disk, even after the team kicked her out.
- Real After All: The ghost of Fernando el Aguirre appears at the end, speaking one mysterious word: Nibiru.
- Secret-Keeper: Velma decides to keep quiet about Marcy being Dark Lilith, instead pretending she just flew off and left the Planispheric Disk piece behind.
- Shout-Out:
- The episode title calls to mind House on Haunted Hill (1959), "Night on Bald Mountain", and possibly Escape to Witch Mountain, though none of these are directly referenced within the episode itself.
- The handprint painted on a soccer ball is a reference to "Wilson" from Cast Away.
- Skull for a Head: The ghost of Fernando el Aguirre's face transforms into a bare skull as he laughs menacingly before vanishing.
- What Happened to the Mouse?: Boron suddenly disappears after revealing the ship to the gang and never reappears again.
- Velma: Well, gang, with the 3 pieces we have, the two pieces Pericles stole, that means there's...
Scooby: Just one more piece to go.
Daphne: Yeah, and why do I get the feeling that even if we don't find number 6? It'll end up finding us.
