Meltdown in the Magma Zone!

Xros Heart escapes from AncientVolcamon's clutches, but Tactimon is coming to stop them.

Synopsis
After being discovered by AncientVolcamon, Taiki and his group are captured. After surrendering and tricking AncientVolcamon with a false Xros-Loader, they're sent to a cell deep in the base. It's here that Cutemon finds his parents were transferred to a separate base the previous day. Although upset, Dorulumon explains he should be happy to know they're alive. Meanwhile Taiki tries formulating a plan for escape, but the other Digimon with them refuse to help for fear of how the Bagura Army will punish them. But after Taiki encourages them and tells them it'll be painful either way, they agree to help dig a hole out of the cell. Encouraged by Taiki's speech, Dorulumon uses the drill on his tail to help free them too. But somewhere else in the lair, AncientVolcamon discovers the Xros-Loader was a fake. His anger rocks the cave as the others run for fear of a cave-in. But when they reach the other side, an army of Meramon are waiting to ambush them. Shoutmon and Ballistamon DigiXros to Shoutmon X2 and mow down the battalion. After that, they're met by AncientVolcamon, who's angry yet again. Along with Dorulumon, they DigiXros to Shoutmon X4. But even then they're no match for AncientVolcamon. Only after Taiki realizes they must plug AncientVolcamon's spout are they able to stop him. AncientVolcamon's lava back-flows and he explodes into data. But just when it seems they've won, Tactimon appears on the horizon to reveal a dark truth: Dorulumon was once part of the Bagura Army!

Digivolutions
(Number indicates order of occurrence.)