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.

When the group is attacked, Tai and Agumon are hesitant to fight since Digivolving into SkullGreymon. Piximon rescues and trains the DigiDestined at his facility, where Tai and Agumon are stranded in a cave as the others do manual labor. At night, Matt and Izzy sneak away to find the Crest of Friendship and the Crest of Knowledge. However, they are detected by the Dark Network as Etemon sends a Tyrannomon after them. Tai and Agumon regain the courage to fight, leaving to Agumon Digivolve into Greymon and defeating Tyrannomon.