Tomas uses the trinkets to create a strange tonal vibration in the air. What he does next is hard to describe. Half a minute of magical trap disabling later...

For a moment, there's a barely visible energy fluctuation. The enchantment aura ceases to exist. The magical fields covering the sarcophagus shift in strange ways. 

"It's disabled. Should be safe to touch. None of the jewelry is magical."

"Lhín thinks she would have been immune to the trap even before you disabled it. I suggest we let her do any object confiscation in case something strange happens."

And assuming there are no objections, Lhín will dart in and scoop up as much of the jewelry as she can reach! The body itself is just an impediment, and the clothing seems impressively well-crafted in some way she has never seen before, but the jewelry is the thing directly worth money here.

(The clothing is also ridiculous in other ways. Lhín isn't squishy enough to have strong opinions, but Sorshen certainly had no problem showing off her body if she wore things like this. That would make her one of the Lust runelords, so an enchanter? That seems consistent with the trap, and with the statue from before. Her elf should have realized this by now. Not being squishy does have its advantages.)

Lhín collects a necklace of lapis lazuli, a pair of emerald-studded earrings, seven metallic rings, and a silver and pink pearl anklet. The body is warm to the touch.

These are more delicate than the hydra's jewelry. They haven't been damaged. A similar solid box should still work just fine, though. Out and to the others for proper storage.

"She is not all dead!"

"What do you mean?"

"She feels like a sleeping person, not like a dead person! She is not moving and I do not hear a thump but she is warm."

Well that's interesting.

"Lhín says the body is warm, but she does not hear a heartbeat. I have no knowledge of what that indicates."

Tomas shrugs. "Neither do I." He peers at the jewelry. "That will be worth a lot. Thousands of pounds on the international market."

"We should probably move forward. Left or right?"

"Well, if she is going to suddenly awaken from her slumber after we opened the sarcophagus, I suspect there is little we can do about it. More water to the left, so I say we start right, and go left only if you have a slot for the raft spell after seeing what else is here. Swimming a river is dangerous, and I would not fully trust any transport systems to work after however long it has been even if there are any."

Julen leads them around the corner to their right and down the hallway.

The hallway is held up by columns carved in the shape of Sorshen. Each one wears a different outfit and they're all in various states of undress. It ends at an immense panel of reddish metal nearly twenty feet tall and ten feet wide. Dozens of scenes have been carved into individual one-foot-square frames on the panel. These scenes chronicle a beautiful woman engaged in a magical incantation involving some sort of winged creatures.

"That's a door!" Lhín zooms up to take a closer look at the scenes. If this is a door, they must be here for some reason.

"An impressive display, and it seems to also marks a passage. Tomas, perhaps you can find the opening?"

Tomas peers at the door. "I think it opens if you press one of these squares?" He gestures at a set of panels.

The images depict a powerful wizard infusing objects and locations within this place with succubi, likely to power magical effects and traps and serve as guardians. The central panel depicts Sorshen binding a particularly powerful looking succubus into what would seem to be the scepter held aloft by the Lady’s Light.

"That is a worrying number of things with succubi bound to them, if those succubi are still there. Thousands of years is a lot of time to escape..." Is one of those objects identifiable as the statue from outside in the solifugid cavern?

One of the objects is indeed the statue from the solifugid cavern. There aren't any solifugids in the image.

She points it out. "At least one of those bindings has held for this long. Yanor, it would be good to have at least one Protection from Evil available on need."

What does a Detect Magic see on the door? Conjuration, enchantment, and maybe some abjuration for containing bound succubi? Do any of the scenes show succubi being bound into this door?

Yanor sighs. "Demons. Just what we needed. I can prepare protection from evil if we want to take a break for fifteen minutes."

"Don't worry too much. I brought a pair of cold iron weapons."

The doors are not visibly magical. None of the scenes show this door in particular.