Lost Lab of Kwalish

Also, I recall there being special rules on movement in the Astral Plane; Wile, could you please pull those up?

Ooc: Forgive my possibly erroneous narration. Her answer should render accurately as she is causing  the effect with the intended result, pardon my prose for potentially describing otherwise.  If you want to see if the sphinx actually knows that answer, here's a dice roll. 16 DC15.

Regardless, you're stuck with this.  Either you'll have to 1. ask the Sphinx for a trade or 2. pay the toll or 3. fight her and figure out how to get back.  These are the choices atthe moment.  The Sphinx believes she has answere correctly abd will exact rhe toll unless option 1 is selected.   I guess a fourth option, running away also works.

Movement on the astral plane is an exercise in thought. Your speed is 3 times your intelligence modifier.  The Sphinx has an Int score of 24 (+7) so a movement of 21 (I would pose that on tbe astral plane, these are relative units as distance units don't quite fit)  in general things on the plane are closer or can be reached faster the more familiar you are with them.

What sort of trade, then? Asking a different question, or offering her a physical object?

As Huarache begs the sphinx to bargain, she stares with her ever inscrutible exoression at the smaller cat-person. Its hard to tell if she thinks of Huarache as more of an inverted parallel of herself or a fuzzy plaything to abt around as it squeeks.

"I have no use for trinkets.  I covet nothing less than knowledge.  Pure, purrrr-fect knowledge.  Among the residents across the chasm where we met, there are ancient brains, preserved in glass; all of them creatures with advanced intellect and a unique perspective on the world.  Find the brains and bring one to me.  If yiu will do this, you may pass freely." the sphinx replies.

"Alright," Huarache agrees.

In a vastly anticlimactic nod if ascent, the s0hinx transpirts herself and everyone elae back to the orime material plane where they stood just moments prior.

"... Three, four, five." Mary counts as she points to the returned members of the party.  "Glad you all made it back.  Surprised, frankly, but pleased as punch you all decided to rejoin us."

At the Sphinx's mental command, a pulse of fire flowering marks something igniting across the chasm, from the edge of what you recognize as an island, floating above the canyon floor below. Alongside its distant dock. Something  detaches and floats smoothly towards you—a flying skiff piloted by a hooded figure.

"That was a doozy." Omiy comments, as she catches herself being a little carsick (?) traversing through planes. She looks at Huarache, "did we agree to do something for her? Oh, I'm seeing stars, and something else." She says, squinting her eyes as she trying to focus. She sees the tiny point slowly enlarges as it approaches them, that looks like some kind of floating boat, "that looks real." She adds.

"Yeah, I see it as well. She wanted us to get some jarred brains in the building across the way there because I made the terrible mistake engineers fear: using weight instead of mass. I'm gonna be kicking myself for years over that."

The skiff approaches quickly, slowing as it nears the dock at the edge of the cliff.  The pilot does not bother with any clumsy rope or chain to moor the skiff to the dock, but it seems to be held fast in place.  The hooded figure stands at the helm, not particularly looking at any of you, just facing the bow of the skiff.  He does breifly acknowledge the sphinx with a nod of respect.  

Up to ten creatures can fit on the skiff in addition to the pilot.  A DC15 perception check can reveal the cowled visage of the skiff's pilot.

Perception: 13

Huarache notices that beneath the robes, the pilot has the same bony face as the monks you saw earlier in the magic vault.  In fact, one who has been here before might week recognize the floating island ahead as the Monastery if the Distressed Body.

Along with the supernatural control of the skiff displayed by its pilot, one might reasonably guess this to be a merrenoloth.

"Well, all aboard I guess." Mary says, slipping her cards bsck into their leather pouch before stepping into the vessel, followed by Ctenmiir.

Ooc: I just realized that I was expecting PCs to state they were stepping onto an hoverbarge. I see how unrealistic thst expectation was. Im jot controlling your characters; tell me if you wanted to do something else.

The group boards the barge, but it doesn't move. Ctenmiir, noticing this, helpfully comments: "Why aint we mivin'? This dinghy ain't fit for the voyage or what?"

Mary strikes Ctenmiir with a mind sliver 2 DC14

"We're expected by the grace master."she says flatly. Regina into her coinpurse, she finds ten pieces of platinum and have them to the ghoulish gondalier "For your trouble."

The ferryman takes the coins, wordlessly pockets them and the skiff begins to move.

Ctenmiir save: 21

A figure dressed as a hooded monk stands besides the dock, awaiting your arrival. Though he does not lower his cowl, he greets you warmly. 

“Congratulations on your finding us! The Monastery of the Distressed Body remains ever open to new prospects. I am sure the Grand Master will find suitable use for your bodies . . . or your minds. May I take you to him now?”

Considering backstory, rhis place would be familiar to at least one of you.

If you want to make any checks, go for it. I'm not going to call for them.

Hondo sees that they are at the Monastery. “Uhh. Guys? I thought we’re going to avoid this place. Remember? Me? Here? Slavery? These guys are not to be trusted.” Hondo will try to hide among the group. 
Stealth: 27

"Doesn't seem like we have much of an option." Leann says with a frown. "If they give us trouble we'll just have to take care of them..." With a glance to the others she waits to see if they wish to go see this grandmaster or not.

Ooc: its kindda where the story hsppens, so going back the way you came in kind of thing maybe.  We never really dod work out how yiu escaped.  Throw me some ideas or we can keep handwaving it.

He doesn't recognize you.

It’s not like we are here to make friends, we are here to take their brains, right? Omiy patted Hondo’s shoulder reassuringly, and climbs off the skiff. “Yes sir,” Omiy says, “please show us the way.”

P.S. She wants to see if he’s still got a face under the hood. 

Omiy: make a perception check to see if you can flimose beneath the monk's hood.

"Very well. Please, follow me to the central abbey." The monk replies. "I was once known as Lean Meimbaol. We receive few visitors in these remore parts, but newcomers are welcome. We are always looking to bolster our ranks. Who knows, perhaps some among you will join the 'enlightened ones'?"    

At the surface level of the floating rock island, the monastery is laid out as a large campus composed of sharp-angled buildings. These jut out of the ground like massive metallic crystals, with scraggly gardens set between them and paths winding throughout. Five monks led by an elder can be found here, silently going about the business of gardening, observing prayers, scrubbing flagstones, and other mundane activities.

Anyone may make perception or investigation checks.

Ooc: Remind me, who has the rod of the mercurial? Where do you have it?