Lupin is framed for the murder of Inspector Zenigata by a mysterious assailant wielding a silver‑colored Walther P38 pistol that Lupin himself once owned. Pursuing the true killer leads him to an island inhabited by the blood‑thirsty Tarantula assassins inside the Devil’s Triangle. Forced to ally with the spider‑tattooed army, Lupin and his gang forge new friendships and enemies as they plot to seize the Tarantulas’ massive gold hoard while hunting the shooter from Lupin’s past. Can Lupin finally silence the demon that haunts his memories with the Walther P38?