Going directly to the ruins doesn't work, but remember The Girl's blue-haired friend? We find her still wandering around by the south exit from town.

Then, with a sudden noise...

A number of townspeople and masked figures roam around, none of them responsive. Pamela stands by the entrance to the ruins proper, though.

Pamela strikes The Girl, knocking her back a few steps, then walks past the guards and inside.

The Girl muscles the guards out of the way.

So the party goes inside, where a distinctly eerie tune plays (track 32 儀式 / "Ritual").

Luckily, the ruins turn out to be in surprisingly good condition for anything called that. However, they're unsurprisingly full of monsters, many of them undead. Those, combined with creepy decor, complement the music to create a rather unsettling air.

Be careful of the Dark Priest (Tomato Man) in particular, as it will summon Zombies, while its high defense and evasion make it very difficult to harm with normal attacks. Freeze will kill one with ease, though, and charged attacks may also work. Zombies sometimes appear on their own, as well, and have a poison breath attack. Other monsters include the Evil Sword (don't mistake it for a decoration), and more of the Unicorn Heads seen previously.

Deep in the ruins, the party finds an intimidating figure standing atop a prominent raised platform.

A familiar blue-haired girl appears behind him.

Thanatos steps back, and a familiar blond soldier appears behind him.

The floor underneath the party vanishes, dropping them into a large room with spikes along the near wall.

The boss music starts. Above, the party finds a wall with a pair of Guarder's Eyes (Chamber's Eyes) and a third eye called the Room Guarder (Wall Face). They use a variety of magic attacks, including Dropper (Energy Drain) to drain health. Conveniently, all have an air affinity that leaves them weak against earth magic. The center eye is the main target.

If using weapon attacks, strike when the third eye opens. Killing the side ones may help reduce the number of attacks you have to deal with, too, but with both dead, the wall will start advancing toward those spikes at the bottom of the room, resulting in an instant Game Over if it gets all the way there. However, a few Diamond Missiles (Gem Missile), preferable to Earthquake (Earth Slide) for MP efficiency, should take it out too quickly for it to cause much trouble at all.

"Orphan of the Storm" plays after victory as the party goes to confront Thanatos again.

The Girl rushes forward as Thanatos disappears with Dirac and Pamela.

Thanatos's voice sounds from nowhere.

That should have saved the townspeople, at least. Let's try talking to some of them.

Pamela's missing grandmother is among them.

And so is Gemma.

してんのう (shitennou, often written 四天王) is one of those terms that I'm finding comes up constantly in fiction. The original meaning comes from Buddhism and refers to four great kings watching over the cardinal directions, but in colloquial use, it can mean any group of four who excel in their field or hold particularly high rank in a power structure. The translation that appears in the Pokémon games works remarkably well.

And with that, the party exits the ruins. However, checking the status screen reveals something troubling: the Water Seed has disappeared from the Mana Energy readout! It seems Gemma may have had the right idea when he suggested visiting Luka.

Note that while Mana Energy now displays as 1, it's still functionally 2. Feel free to keep raising any spells that haven't already reached that level.

But first, let's go see the king. The cheerful "Color of the Summer Sky" now plays in Pandora instead of the gloomy "Roses and Spirits".

The guard gets out of the way, and downstairs six treasure chests await. Most just have a bit of money, but others...

Not bad, though it's anyone's guess how those got there or how they were stored. In any case, the previously nonfunctional shop in town has reopened, though Cobra Bracelets are the only thing they sell that count as new at this point. At least the townspeople generally seem appreciative.