Zhang would cast Light on Lan if he wanted otherwise on himself as they explored. Zhang nods at Xi’s suggestion.

“It would be good to gather as much information about this place as possible Maybe we can find answers to all our questions and more. I can use my elven eyes to search for anything magical in nature.”

Zhang, using his elvish ability, casts Detect Magic before moving into the room. In addition to looking for anything that is magical he will also search the room for anything of interest.

Perception Roll: 18

Lan tilts his head toward the faint glow, thumb worrying a prayer-ridge on Stone-whorl. “A room that shines inside a tower larger than its skin,” he murmurs, voice low. “When stone lies about its size, better to hear its story before climbing higher.” "Cautious is not cowardly," Shí-Guāng rustles in the back of his mind. "Just lived-long." He nods once to Xi’s suggestion. “The light first.”

He eases forward with the others, offering the butt of Stone-whorl if Zhang wishes to set a Light upon it, then slips down the left passage. Staff tip tests each flagstone; his free palm rides the chill wall. The shelves and lone desk resolve in the glow, dust motes turning in slow eddies. Lan keeps to the room’s edge, counting heartbeats under his breath, eyes tracing joints, cracks, and seams—anything that tells how this place was meant to be used, and by whom—before he dares the center.

You turn left, towards the room, hoping to glean something about this place before you continue upwards. However, after walking about ten feet down the passage, you feel a strange sensation -- as if a hundred butterflies were twirling around your stomach. You can't quite place it, but you feel that something is wrong. 

Zheng, you sense plenty of magic throughout the entire tower -- this wizard's certainly been doing their work. You sense a huge amount of magic coming from the room ahead, but it blurs any tiny, weaving strands of wizardry that could be flowing through the walls. 

Everyone roll a Dexterity saving throw.

Dex save: 19, if advantage from dodge applies: 21

Dex save 10

Dex Save: 14

(OOC: Dang, those are all pretty good. Although one of them isn't quite good enough, I'm afraid...)

You come to understand your feeling quickly and simply, with a whoosh and a sudden shout of surprise. As Lan and Zhang look around, they see no sign of Xi. Looking up and down the passageway, you still don't see any sign of her. But then, a sudden shout of "Up here!" draws your attention -- Xi stands on the ceiling, twenty feet above you. She flails for balance for a few seconds and instinctively puts her hands up as if she was trying to block her fall, but then stabilizes.

Lan freezes mid-step, head tilting back until the torch-glow finds Xi clinging to the ceiling. Stone-whorl rises slowly, testing the air above like a blind man’s cane, then taps the flagstone at his toes. “Hnh. Snare of some sort,” he mutters, eyes narrowing along the seam where floor meets wall. “Do you need a hand up—or down?”

(To clarify,, is this a magic effect or a rope snare  I'm answering as if it's magic, )

"Well if you could catch me if I fall that would be good"

Meanwhile she looks for something to tie a rope to, and might as well look for trapdoors up here in case this effect is what passes for a elevator.

Perception   20

Quote from Arthuropodd >>

(To clarify,, is this a magic effect or a rope snare  I'm answering as if it's magic, )

"Well if you could catch me if I fall that would be good"

Meanwhile she looks for something to tie a rope to, and might as well look for trapdoors up here in case this effect is what passes for a elevator.

Perception   20

(This is a magical effect, as far as you can tell -- you haven't been pulled up by a rope)

Xi spies no trapdoors on the ceiling -- it appears that this has been specially brewed up for intruders. But, looking around, she spies a small brick protruding from the wall above her (since the floor is the ceiling) that might serve as a rope-hold, although it does look like it might fall out with a lot of pressure. 

Xi tries to tie one end of the rope to the brick & the other end around her waist, such that she can let out rope if needed.

19

Zheng looks at Xi.

“Good idea. I will see if I can find a way to release the magic from down here.”

Zheng attempts to understand how the magic works and see if there is a way to reverse it. Zheng is concentrating on detect magic if that helps him.

Acana Roll: 14

Lan plants Stone-whorl like a piton, feet shoulder-wide, eyes tracking Xi’s center of mass while he rolls his shoulders loose. “Aye—if you slip, I have you,” he says, baritone steady. He counts three slow heartbeats, testing his stance against the flagstones, then raises his arms to gauge the fall line.

“Lower the rope when you’re set,” he adds, planning on looping its end around the staff’s dragon-spine to make a makeshift fairlead should he receive it. “I’ll haul you toward the right downside—slow and even—so the floor becomes your floor again. Anything interesting up there? Just curious since you're already there.”

Slowly walking towards the loose brick, Xi carefully bends down, tying a rope to the ledge. The brick shudders with the force for a second, then lies still, the coil wrapped around it. 

Quote from JehanO >>

Zheng looks at Xi.

“Good idea. I will see if I can find a way to release the magic from down here.”

Zheng attempts to understand how the magic works and see if there is a way to reverse it. Zheng is concentrating on detect magic if that helps him.

Acana Roll: 14

Zheng, looking for the perpetrator of this trap, feels a certain magical presence now that the trap has been sprung -- a subtle strand of magic, pulling Xi up, which loops towards the room in front of you. However, this coil feels taut -- ready to yank others up onto the ceiling as well. Perhaps the trap was meant to release intruders only when someone was already among the bookshelves ahead?