Goth, a living skeleton model, shares the science room at St. Claire Elementary School with Kunstlijk, an anatomical model. Facing imminent extinction due to the room's scheduled demolition, he actively seeks salvation while Kunstlijk initially expects relocation. When three girls vandalize their exhibits, Goth rejects Kunstlijk's vengeful impulses and recruits the girls for the After School Midnight Party—a challenge series where three medals grant a wish. He pragmatically believes their wish could save the science room.

Throughout the quest, Goth mediates between Kunstlijk and the girls, physically restraining Kunstlijk when his anger escalates toward violence and offering indirect aid during challenges. His forty-year history with Kunstlijk includes witnessing an incident where debris from Kunstlijk’s future time machine made it appear he willingly gave a medal to a participant, damaging his reputation among the Midnighters. Goth also participates in Kunstlijk’s experiments, including reviving three preserved rabbits; when one rabbit vanishes through the time machine, the others become aggressive and pursue Kunstlijk.

In spin-off media, Goth and Kunstlijk continue nightly experiments and research in the lab, navigating supernatural occurrences amid their collaborative yet contentious dynamic. After the girls succeed and wish to "play again," the science room is saved from demolition. Goth and Kunstlijk are restored to prime condition, with demolition plans erased. A post-credits scene hints at their ongoing adventures.