The kids run away from a Monochromon battle. They come across a trolley car on a small island and decide to spend the night in it, until they are attacked by a Seadramon.

The kids meet the ruler of File Island, Devimon, the controller of the Black Gears.

Joe's tag leads the DigiDestined to a coliseum, where Etemon traps them and forces Greymon to fight another Greymon. After Joe finds the Crest of Reliability, the group escapes and Tai forces Greymon to Digivolve to his ultimate form by putting himself in harm's way. Instead, Greymon Dark Digivolves into SkullGreymon, attacking everyone before eventually reverting to a regretful Koromon.

Piedmon turns the DigiDestined and their Digimon into doll keychains. With T.K. and Kari remaining, T.K. imagines Matt giving him advice, regaining hope and activating his Crest. Angemon Digivolves into MagnaAngemon and saves the rest of the DigiDestined, and together, they defeat Piedmon when Mimi reunites with the group. The DigiDestined are unable to celebrate their victory when they receive an e-mail from Gennai, who reveals that another enemy is the true cause for the destruction of the Digital World.