Right after Kari wakes up and is back to health, Sora and Biyomon as well as Patamon show up, where T.K. and Gatomon have been taking care of Kari. Sora also hands Kari the medicine that they found, which Tai must have dropped when they became separated. While exploring the underground labyrinth of sewer tunnels, Sora, Kari and T.K. come across a large group of Numemon enslaved by WaruMonzaemon, who is working under Machinedramon. The Numemon are powering the vast city above from the sewers. Kari wants to help free them and begins to glow with a mysterious light. She rescues them and they praise her as 'Queen Kari'. Sora, T.K. and their digimon are busy trying to fight off WaruMonzaemon with no luck as their digiomn can not seem to digivole. They barely escape after he gets his hand stuck in a wall, and find themselves amongst the worshiping Numemon. Suddenly Warmonzaemon appeaers and the Numemon try to fight him off, with no luck, and just as he is about to finish them off, Kari faints again and the kid's digimon are empowered and able digivolve. They battle for a while until he is scared away and Kari begins to glow once more, pointing the group in the direction of the others. Meanwhile WaruMonzaemon reports back to Machinedramon and tells him that he fought with the DigiDestined, but was defeated by a young, powerful girl. Machinedramon is displeased with his efforts and kills him. Tai and Izzy are exploring the sewers when Tai gets angry at Izzy and their tired digimon. He wants to continue looking for his sister while the others want to rest. Tai lashes out at Izzy, pins him on the ground and punches him in the face. In the midst of the fight Tai hears someone approaching. They continue to fight (but they are only pretending) and hide from view, awaiting the mysterious figure. Tai then apologies to the understanding Izzy about hurting him and Andromon, the person they could hear coming, approaches. They had previously met on File Island and Andromon is now leading a resistance against Machinedramon, and vows to help the kids safe. Tai and Izzy are relieved to see a friendly face and ask if he has seen the other Digidestined clode by. Andromon, surprised to hear that Tai and 'Queen Kari' are related, informs them that she and the others are headed in their direction when suddenly Machinedramon appears.
After the two groups reunite, the evil digimon corners the them and battles with Andromon. Birdramon, Angemon and Angewomon help him fight too, but the Mega level digimon is too strong for them. Then appear to be beaten so Kari offers herself up to be eliminated first by Machindramon. Before he can strike, however, the hordes of Numemon swarm over Machinedramon in order to protect their Queen. It is of no avail however, as Machinedramon swiftly kills every one of them. The deaths of the Numemon spurs the light in Kari further, and it powers Agumon enough to Warp Digivolve. With his power amplified to unbelievable level, WarGreymon brutally slices Machinedramon, and before he can strike back, he falls to pieces. With Machinedramon defeated, his city begins to disappear. The DigiDestined decide to erect a small shrine to honor the Numemon. With the other Dark Masters destroyed, Tai and the others head off to the top of Spiral Mountain, now ready to face Piedmon.