At Southred Mall, Adventure Club uses Nanana's hint to locate several inscriptions and pinpoint the entrance to the ruins, while Juugo sneaks into the security office and steals a special electromagnetic key. The entrance is in a public location, so they decide to return after the mall closes to clear it. Juugo, Tensai, Yuiga, and Yuu enter the ruins with Daraku and the injured Kagetora standing watch. As with the previous trials, Juugo attempts to brute force the room, triggering multiple spike traps before Tensai reveals the solution to the puzzle to find the safe path down...