The Crest of Sincerity - S1.E17

After getting lost in the desert, the group is taken aboard a ship traveling in the desert, headed by Kokatorimon. Kokatorimon captures all the boys and petrifies their partners. Biyomon and Palmon Digivolve and defeat him, and his ship crashes into a giant cactus. Mimi finds the Crest of Sincerity on top of the cactus.