Taichi’s team reaches an ancient ruin. While Koshiro tries to analyze the characters on the walls, Mimi and Palmon accidentally fall underground. When they’re in danger, they encounter a kindhearted Digimon.

Just when Taichi and his friends thought they had finally defeated the enemy in the fake Tokyo, a new enemy appeared. The children work together with their Digimon to take down the eight-headed Ultimate Digimon.

Devimon’s castle collapsed after the fierce battle with Darkknightmon and Taichi’s group comes to face Devimon at last. Meanwhile, the rest of the Chosen Ones and their partner Digimon fight to destroy the obelisk that is transferring energy.

Taichi and Agumon act as bait so that the jungle’s Digimon can safely escape. However, Metalgreymon’s attacks are useless against the new Mega Digimon that stands in their way.