The DigiDestined have each attained their Crests and aim to reunite now. However, they receive an emergency call from Wisemon and Garbagemon that the laboratory is under attack. The DigiDestined fight to protect the lab from a swarm of Digimon.
T.K. and Patamon are warned in a vision by Devimon of the impending Great Catastrophe that is coming, as that is what caused him to become his more crazed and psychotic digivolutions of NeoDevimon and DanDevimon. When the vision ends, T.K. and Patamon are reunited with Kari and Gatomon, before they and the other DigiDestined head back to Tree of Information to regroup, especially when Wisemon and Garbagemon send out a mayday call as the Tree is under attack by the Soundbirdmon, who have brainwashed the Mekanorimon to aid in their assault. Once the DigiDestined arrive to assist, though the room where the Crest slabs are is untouched, the Soundbirdmon soon merge into their combined form of Ghoulmon, which Wisemon describes as the herald of annihilation, despite being born of darkness itself, while more Soundbirdmon assault other parts of the Digital World where many of the Digimon the DigiDestined met and befriended, like Leomon, the Tanemon, ShogunGekomon's group, Rebellimon, Whamon, MarineAngemon's group, Muchomon, Burgermon and Jagamon, Nohemon, Etemon and Volcamon, Golemon and the Gotsumon, Neemon's villagers, and Lopmon's group, watch in muted shock and horror as the omens of the Great Catastrophe begin to manifest, yet refuse to give up hope on the DigiDestined saving them from destruction.
Ghoulmon attempts to destroy the Crest slabs, but is stopped by MagnaAngemon, Angewomon, and WarGreymon, before T.K. and Kari are able to bring the full power of their Crests of Hope and Light to bear, and MagnaAngemon and Angewomon digivolve into their Mega forms of Seraphimon and Ophanimon. With their angelic powers, Seraphimon breaks up Ghoulmon's ultimate attack, while Ophanimon delivers the killing blow, causing all the Soundbirdmon to die with Ghoulmon. However, Ghoulmon warns the DigiDestined with its dying breath that the Great Catastrophe is about to begin as Ghoulmon's presence was merely the herald, while back with the Ultimate Argomon, his master, Negamon, finally hatches from the orb that it was contained in.
Back at the Tree of Information, once the DigiDestined are gathered, they are thrown into a vision where the Crest slabs glow fiercely before vanishing, much to everyone's confusion. However, they soon are summoned to see that Negamon's Great Catastrophe has begun as cracks in the Digital World's dimension have begun to appear, revealing nothing but a white void, just as Devimon had forewarned.
(Numbers indicate order of appearance. Bolded characters are fought by the protagonist(s), and italicized characters feature non-explicitly, e.g. voice, silhouette, image.)