S1, E5: Moments after Thomas defies Sampson's orders and transports himself and Gaomon to the Digital World, Marcus sneaks into DATS, too. With no one else at headquarters, Marcus threatens to break the Digital Dive machine unless Yoshi helps him go to the Digital World to finish his fight with Drimogemon. She grudgingly helps Marcus with his Digital Dive, but only so he and Agumon can bring back Thomas and Gaomon. In the Digital World, Marcus and Agumon soon come face to face with Drimogemon again. Drimogemon easily traps them underground, and they are reunited with an injured Thomas and Gaomon. They were also outmaneuvered by the drilling Digimon. Thomas reluctantly accepts Marcus' help to find their way out the underground den and defeat Drimogemon. The foursome find Drimogemon. Instead of waiting until they're at an advantage above ground, Marcus attacks! He forces Drimogemon to the surface, riding him like a bucking bronco. Then he steers him to an ice arena, where he can't dig to escape. Geogreymon and Gaogamon combine their attack spells and defeat Drimogemon, who had digivolved to Digmon. Back at DATS, Sampson scolds Marcus and Thomas, but is relieved they are safely home.