"On your own? Perhaps the goddess did send you in answer to my prayers."

Man if so that's. That's too many. Too many spirits from outside Mundus taking an interest in him.

"How do you know all this?"

"I have dealt with this group of cultists before, and have witnessed their practices."

Right. Elves. "Decades" doesn't mean much.

The temple is a tower overlooking Dawnstar from the east on a mountaintop. After dispatching an Ice Wraith that had made its home there and checking that there aren't any other surprises around they walk into the temple.

And as soon as they do, there is a moment of distortion, a feeling of dizziness as a wash of magic covers them—

—and all of their equipment disappears. Their clothing, the mace Erandur had been carrying, their enchanted jewellery, their extended pouches.

All of it—except, that is, for the Sanguine Rose, the staff Sanguine gave Ruby.

He starts swearing profusely.

"...this is not a security measure I'm familiar with," Erandur says, after he's recovered his balance and is looking around. "It's ingenious, stripping invaders of their equipment, but I have no idea how it could be accomplished."

"...no, I think that's, uh. That's not a security measure. That's a prank."

"How do you mean?"

Ruby leans over to grab the staff and sigh. "My turn to disclose some not exactly secrets: the Daedric Prince of Hedonism, Sanguine, has taken a liking to me, and has said that he wanted to see what I'd do, in the future. This—" Gesture at staff. "—is a staff he gave me. I am starting to rethink my life choices, here."

"—you're a cultist."

"—no! Absolutely not. Sanguine's, like, a cool guy, I guess, but I am not a cultist. She just... thinks I'm hot, I guess."

"The Daedric Prince of Hedonism... thinks you're hot. In my experience, drawing the attention of Daedra Lords is not wise."

"I didn't have much of a choice, honestly, he sent me on a merry chase around Skyrim and then decided she was going to keep me."

"You chose to bring that staff with you."

"—fair enough. But it's a really good staff." Here's the Dremora—or a Dremora, it doesn't look identical to the last one he summoned even if it's in identical armour and has identical facepaint, but they have in fact told him that they don't like being seen as individuals so he'll do his best to just think of it as the same entity as the previous times he's summoned them.

"...I suppose having a physical combatant like that is not an advantage to be ignored. Though I am not sure it is worth the price, if all of your equipment is gone."

"I... expect it's not gone, gone? It wouldn't be Sanguine's style. He'd have a lark about us misplacing our stuff but my expectation is that we'll get it all back once we're done here. And she knows most of my firepower is independent of my equipment, anyway."

"Very well. I hope you're right."

He advances, and this entry hall looks very much like a church, even if one dedicated to a Daedric Prince: there are pews before an altar, a graven image of the Daedroth behind it, the whole shebang. And there is indeed a small shrine to Mara next to a wall with some offerings and her holy text.

But also there don't seem to be any doors or stairs to anywhere.

Presumably the seal also placed an illusion or something. Ruby will just explore this chamber and wait for Erandur to do his thing.

Indeed. Erandur starts casting some complicated magic on the graven image, and seems wholly engrossed in this for a while.

Ruby dismisses the Dremora, then, since it seems like this will take a bit. Which makes sense, a seal you could just unmake over a few minutes is basically useless.

...which brings the question of how Erandur can do it at all. It doesn't seem like he's brute forcing it or trying to do the magic equivalent of hitting it with a battering ram, so that's curious. Ruby has a little hypothesis here and depending on which half of the hypothesis is true he might just be in a lot of trouble.

He hopes not.

"It is done," says Erandur at the same time as the graven image—and the wall behind it—suddenly turn translucid and, as demonstrated by Erandur walking through them, intangible. "Be on your guard; if my guess is right, the more the Miasma seeps out of the temple the more people will wake."

"The Miasma" is probably the low-hanging purple mist that seems to permeate the place and that is, indeed, seeping through the no-longer-solid wall. Ruby resummons the Dremora, casts Stoneflesh on himself, then conjures a bow and a quiver of arrows—he found out recently, while hunting in the wilderness, that he's passable at it, probably courtesy of his past life, and this here seems like a good opportunity to practise more. The staff he holds Telekinetically; if he's not doing anything particularly complicated with it he can just make it hover after him at a fixed distance while paying barely any mind to it.