"Upstream or downsteam? The raft can do either."

"Upstream should lead to the other direction from the start? Best to check that now and avoid the need to later retrace our path." Raised eyebrow at Julen, inviting him to chime in. He claimed to have some training in navigating the outside, and this isn't truly outside but it seems to share some traits.

"Sounds sensible to me."

Yanor commands the raft up the river.

The waters of the river are dark, while the walls are a breathtaking array of earthtones, the natural stone polished and smooth. They pass by a balcony around ten feet above the surface of the water. The familiar statue pillars are visible down the hallway it connects to. The river continues past it, making a slow turn.

"It looks right to me, and I recognize some of those statues. We can sweep it for distinctive magic on our way back if we choose, but pending that I am happy to call it examined and properly looted." Nod.

"This water must have both source and endpoint, and both are of interest if this area is as sealed as we believed. This done, I have no strong preference in direction. Do any of you?"

"Continuing upstream to the source seems like a fine idea."

Tomas nods in agreement.

"Upstream it is."

Yanor commands the raft up the river.

A churning cascade of water pours from a circular hole in the highest part of the wall here. A metal grate covers the hole, and glowing runes surround the hole’s rim. Along the south face of the watery tunnel, an oval stone platform protrudes from the wall, forming a sort of balcony over the river. At the back of the platform’s alcove stands a twelve-foot-tall stone statue of a beautiful woman, her arms raised up in the air.

Yanor brings the raft to a slow stop near the oval platform. "Do you see that?" He points at a half-submerged large crack in the wall ten feet east of the platform. Water rushes down it. "Some sort of passageway..."

"Definitely of interest. I see no easy way to go through there, though. The transport methods we have seem unlikely to fit, and if it becomes submerged Lhín would only get stuck beneath the river's force... Possibly Julen could make it with the Ring of Swimming, but traveling alone seems quite risky. Certainly only after examining the source. If this is a water creation item with enough scale to supply a river —" She stops for a moment. "Well, we can't exactly remove it from the area, and it is probably too costly in spellsilver to be reproduced. But what an incredibly useful item! The Abadarans would pay just for knowledge of its location, even with no assurance of a way to extract it from the area."

"Indeed." Yanor disembarks onto the oval platform. "From here we can get a better view."

She gets off as well, and Detects Magic, aiming it first at the statue of Sorshen. If there's any trap here, that's the obvious location for it.

The statue radiates a strong enchantment aura.

Does she remember seeing a succubus stuffed into this statue back at the door with all the images of bound succubi?

She does not.

Interesting. "This could be the same spell as the statue from outside, but I don't remember Sorshen binding a succubus to it back on the large door. Tomas, can you tell if it is a magic item or otherwise a trap?"

Tomas studies it for a few moments. "It's not a magic item or a trap. I don't know anything else about it."

"Spell, then, and I certainly don't know of many powerful enchantments placed on objects besides whatever Sorshen used to tie succubi to them and standard Symbols. Of course, my knowledge is rather incomplete, and even optimally I would know little of Thassilon's spells. Do any of you have an idea?"

Nobody else has any ideas. The spell must be at least seventh circle. Enchantments that target objects are uncommon.

"I'm going to take a look at the water grate." He walks over to the west edge of the platform.

"Tentatively assume there is some other sort of powerful outsider bound to the statue, then? I think it safest not to touch it, which I suppose is unsurprising."

And now, what does Detect Magic have to say about the grate and its surrounding runes?

The grate and surrounding runes emanate a strong conjuration aura.