Nuoren naisen on ratkaistava vaarallinen labyrintti pelastaakseen veljensä, jonka peikkokuningas on napannut hänen toiveestaan.

Scooby-Doo and Shaggy must go into the underworld ruled by The Goblin King in order to stop a mortal named The Amazing Krudsky who wants power and is a threat to their pals: Fred, Velma, and Daphne.

Underlying disorder in Jared and Amy's relationship comes to a head when Jared becomes monomaniacally obsessed with going Goblin Mode.