Joined by Sora and Biyomon, Tai and Agumon soon reach a castle guarded by a Knightmon, who steps aside to allow them entry into the castle. After they enter, the Knightmon kneels for a shadowed figure that rushes in behind them. Tai is soon separated from the others and encounters a glowing figure that reveals to be the spirit of Valkyrimon who perished in the ancient war. It then skewers Tai while asking to show his true power, before Tai awakens in a desolate forest under a blood red moon, unable to reach Sora, where he soon encounters a Botamon being threatened by a Goblimon and rescues it before hiding from the Goblimon as it searches for them. As Tai then takes the Botamon to go find his partner and friends, he recognizes the bird from his vision, before being attacked again and forced to jump into a river to escape, where a Seadramon attacks him next, but Tai manages to make it to dry land, forcing the Seadramon to give up and leave.
After the Botamon wakes Tai up, he sees the same bird again and follows it once more, but is then attacked by a pair of Allomon. Taking a desperate gamble, Tai has the Botamon cover him with its bubbles to get through the Allomon's flames, but is cornered by them again. At that point, Tai tells the Botamon to go on without him while he tries to distract the Allomon, making it clear his sacrifice will not be in vain as he's doing it for his friends, showing true courage. This leads to the Botamon undergoing a manifestational digivolution into Greymon via the Crest of Courage and taking down the Allomon in one strike, causing the sword Tai was skewered with earlier to shatter, and Tai finds himself before Valkyrimon's spirit again, who then reveals how during the ancient war, despite their injuries, WarGreymon and MetalGarurumon found new strength, and DNA digivolved into Omnimon to confront ZeedMillenniummon, defeating it in one strike, thanks Seraphimon and Ophanimon and triggering them to digivolve. Recalling when Omnimon was summoned to stop the missile and Nidhoggmon, Tai is then told that the power in his heart that summoned Omnimon would be necessary to defeat the Great Catastrophe, before he is returned to be with Agumon again and rejoined by Sora and Biyomon. While Agumon joins Sora and Biyomon, Tai is notified on his Digivice that he has completed the mystery behind his Crest of Courage, which Sora, Biyomon, and Agumon discover, while Tai ponders over what he was told by Valkyrimon.
(Numbers indicate order of appearance. Bolded characters are fought by the protagonist(s), and italicized characters feature non-explicitly, e.g. voice, silhouette, image.)
Botamon. This is a newborn In-Training Digimon. Botamon cannot fight but can blow bubbles to intimidate enemies.
This episode features multiple references to Digimon Adventure movie with Botamon singing whilst blowing bubbles, Koromon jumping onto Tai's face and kissing him, Botamon quickly digivolving to Koromon, a giant Agumon and giant Greymon, Greymon's Mega Flame resembling the one used to defeat Parrotmon, and the scene of Greymon and Tai just before Greymon de-digivolves to Agumon looking identical to the scene with Greymon and Tai shown during the movie's credits.