Appearing on a moonlit night, the figure in black who refers to Goemon as "the Thirteenth", calls himself "Nezumi-Koozoo IV." He informs Goemon that their ancestors teamed up in the International Thieves' Championship, but were defeated in competition by the original Lupin, and that they should team up to avenge this dishonor. The objective is top-secret data being kept under guard at Sakurada Police Station. Goemon and Nezumi split up, mounting a two-front offensive against Zenigata, who is reinforcing security. What will be the third-generation's next move?