This photo shows the inside of the Palace of the Earth Spirits, which lies at the very heart of the Underworld. Its interior looks just as you'd expect from the outside, with a style reminiscent of classic Western architecture. Why the palace was designed this way remains a mystery. Those eerily glowing stained-glass floor panels hint at the tremendous energy lurking even farther below.

Excerpt from M's report: "Maybe this place really is meant to feel like a prison. After all, fortresses and prisons aren't so different. The Bastille, the Tower of London... The same building can change purpose over time. Or even serve both at once."

Excerpt from R's report: "In loads of old games, the hero gets summoned by the king and asked to defeat some evil overlord. They start in the king's castle. And for some reason, there's always a dungeon underneath it. Back then, I never really questioned why."

Excerpt from M's report: "A prison exists to keep those inside from getting out. A fortress exists to keep those outside from getting in. But both require sturdy walls... aka boundaries. This building feels like a miniature version of the entire Underworld city."

Excerpt from R's report: "A castle, a place of government, built right on top of a prison... Here, it feels like the imprisoners and the imprisoned live side by side. It's like oni and the dead soaking together in a hot spring in Hell. I suppose "oni" originally referred to the dead, huh? The prisoners are oni. And so are the prison guards."