Episode 1 is the first case of the video game, Scooby-Doo! First Frights.
While on their way to Keystone Castle, the gang go to St. Louis High School to see Daphne's cousin, Anna, at her high school musical, only to learn a phantom is haunting it. However, the show must go, and the gang catch the phantom before it's curtains for Daphne's cousin.
Velma arrives at the gang's clubhouse (located in a swamp) with a newspaper, announcing to the gang that there will be a food festival at Keystone Castle. Scooby and Shaggy like the idea of going, but Daphne reminds them that they promised to help her cousin Anna at the St. Louis High School Musical. Scooby and Shaggy want to help her, but they plan to get it done quickly so they can go to the food festival.
Anna is working on the musical with the drama teacher: Ms. Hillken. As Anna works on her lines for the talent show, Ms. Hillken mysteriously vanishes. Her disappearance is partially due to the phantom of the high school musical. Laughing maniacally, he attacks Anna and scares her. She barely escapes.
Investigation: Level 1
The gang then head to the high school. Velma tells Scooby and Shaggy to look for a way into the school by contacting them through the radio. They make their way towards the cafeteria and are informed by Anna that there is a Phantom trying to ruin the musical. Anna tells them where the cafeteria is, so that they can "fuel up" to help Anna in the contest. When they reach the roof, Scooby crawls through a vent leading to the cafeteria, leaving Shaggy deserted. Meanwhile, Fred and Velma are looking for clues. They come upon a baseball field, but the lights are off. With quick use of her technological know-how, Velma turns on the lights. They gather clues and find the Phantom's glove on the field and tell Daphne about this through their radio. Then the school football coach, Coach Hayes, runs by and tells of a way to get in the school and suggests talking with Ms. Hillkin, seeing as she disappears every time the Phantom is around. After the coach leaves, many skeletons attack them. They make their way to the locked door of the school. Meanwhile, on the roof above, Daphne shimmies on a pole and meets up with Scooby at the end of the vent he went through to find food. They make their way in the school, facing off against some musketeer ghosts and six witches so they can open the door for the gang to look for clues inside.
Scooby and Shaggy are chased by the phantom and narrowly escape, avoiding skeletons, electrified floors, pitfalls and falling lockers as they run through the hallways. After reaching the end of the hallway the phantom flies pass them and out a door.
Investigation: Level 2
Fred and Daphne go searching for clues in the library, finding a coach's whistle in the library, tell Velma about it, and suggesting the identity of the culprit. They go to the theater and talk to Ms. Hillkin. The phantom is heard and Ms. Hillkin mysteriously disappears yet again. Daphne recalls that Ms. Hillkin was a famous actress at one point, having won a "Golden Square" award. Fighting past musketeer ghosts and a headless ghost of Shakespeare, after informing Velma about this, Mystery Inc. makes their way to the stage, ready to stop the phantom.
Boss fight level
Fred and Velma face the Phantom, who sings through the whole first portion of the fight. At first, Velma must hack two controls to shut off the lights and coax the Phantom off of his perch. Then the Phantom flies around with the help of four skeletons that are holding him up. The skeletons must be knocked down to commence Stage 3 of the fight. With his flying ability stopped, the Phantom makes one final stand, as he fights Velma and Freddy. After being beaten, he is pinned underneath a pile of loose lighting fixtures. He is unmasked and is revealed to be Coach Hayes. His star player was in the show, which was on the week of the big game, so he tried to get the show sabotaged to get his star player back.
- Mystery Inc. (first appearance)
- Phantom of the High School Musical (single appearance)(Coach Hayes's disguise)
- Coach Hayes (single appearance)
|Anna Blake||She told Shaggy and Scooby-Doo about the Phantom.|
|Ms. Hillken||She always disappeared when the Phantom showed up.|
|Coach Hayes||One of the phantom's gloves was discovered on his baseball field.|
|Coach Hayes as the Phantom of the High School Musical||He tried to put an end to the musical because his star player would be in it.|
|Frank Welker|| Scooby-Doo|
|Scott Innes||Shaggy Rogers|
|Grey DeLisle||Daphne Blake|
|Mindy Cohn||Velma Dinkley|