Tai and Agumon have a reunion in the Digital World. Tai then realizes that Izzy is not nearby, but discovers that Sora has been taken along. As they talk, Tai's Digivice: flashes, brings his attention to a monolith with DigiCode on it, and allows him to read it. They are directed by a light from his Digivice: toward a rainbow mountain in the distance. With no other choice, they head there on foot. Along the way, Biyomon runs into them while fleeing Snimon. Snimon begins to chase and attack the group, proving to be too strong to fight. They jump into a river off of a cliff to escape pursuit, Sora protecting Biyomon the entire time.
Downstream, they escape and rest near a fire, where Tai explains the situation to Sora. Izzy manages to contact Tai from his location in the Network. They update each other on their respective situations, including the Tentomon who has joined with Izzy and the Digital World's location as the deepest part of the Network. Izzy also updates Tai on the spreading blackout in Tokyo and resolve to continue to do what they can. Using the supplies that Sora bought, they craft a raft to travel by river and increase their speed. Biyomon bonds with Sora during their journey. It is not without incident, however, as they first have to deal with rapids and other obstacles and then with an attack by Coelamon.
Agumon digivolves to Greymon to deal with the threat after Tai leaps into the fray to save him. Their problems are compounded by Snimon's return, who attempts to eat Biyomon. Sora latches onto Snimon to save her, distracting it and allowing Biyomon to escape. In the resulting battle, Sora loses her grip. Biyomon dives to save her, and when she manages to grab on, their bond allows Biyomon to digivolve to Birdramon. Birdramon and Snimon get into an aerial battle that ends with Birdramon as the victor, while Greymon successfully deals with Coelamon before de-digivolving. Using Birdramon's wings, they continue their journey to the rainbow mountain, which appears to host to a temple containing statues of Digimon. As they fly off, an Ogremon watches.
Meanwhile, Tentomon and Izzy continue their journey to the Digital World when a Whamon swallows them.
(Numbers indicate order of appearance. Bolded characters are fought by the protagonist(s), and italicized characters feature non-explicitly, e.g. voice, silhouette, image.)
The on the top part of the Digivice: is drawn incorrectly.
The DigiCode on the monolith is close but incorrect to what Tai says it is.
A Snimon is the first antagonistic Digimon to be found in the Digital World. It is a flying Insect-type Digimon, similar to the Kuwagamon fought in the first episode of Digimon Adventure. Both encounters also end with a plunge into a river off of a cliff.
Biyomon digivolved to Birdramon for the first time in the fourth episode, just like the Biyomon of Digimon Adventure did.