While out water-skiing, the gang ends up at Aqualand, where they encounter an anthropomorphic shark-like demon and end up uncovering an attempt to smuggle stolen pearls past the police.
This episode includes examples of the following:
- Accidental Hero: The whole purpose of the "Scooby-Doo" Hoax is because the villain's plans have been thwarted by the park's manager refusing to sign a shipping order which inadvertently keeps stolen pearls from being smuggled out of the country.
- Chekhov's Skill: Mr. Wells cabinet making skills, which is how he was able to get into the Customs building at the airport and steal the jewels.
- Monster in the Ice: The "Demon Shark", an anthropomorphic shark shipped to Aqualand from India.
- Once More, with Clarity: In the beginning of the episode shadowy figure, that appears to be the Demon Shark, steals the jewels in the customs building. After the mystery is solved, a flashback shows that it was actually Mr. Wells who stole the jewels by hiding in a secret compartment he made under the real demon shark.
- Prehistoric Monster: A rare case in that the prehistoric "Demon Shark" is actually REAL... but is still just a frozen carcass, while the supposedly live Demon Shark is another "Scooby-Doo" Hoax.
- Shark Man: The episode's Monster of the Week is the "Demon Shark", an anthropomorphic shark.
- Threatening Shark: Both the Demon Shark and a real one, which chases the gang's boat and causes them to crash into a cliff.
