Letting Khessa speak her idea, Jasper voices an idea after. “I have an idea. It’s harmful but I can strengthen our resolve to lessen the injury. All of us would need to let the Moon Maiden’s light wash over you. The radiant light will reveal the true shape of a shapechanger.” Jasper thinks briefly and looks to the guards.  “If there is such a danger here, all should submit to her revealing moonlight.”

"Katarina is willing, if it will convince paranoid gnomes," the cat says hesitantly, before glancing at the guards. "But would gnome guards even believe light called down by one of us reveals a changer of shapes?"

'Indeed!' Khessa thinks, at Katarina's words 'That's the point... Any method that relies on our resource or knowledge, the gnomes are forced to trust us, if they want to use it... Even if they believe in the efficacy of Jasper's power... how could they know if he invokes it correctly or if, instead, he uses an illusion? If they don't have their own way of detecting these shapeshifters they seem so afraid of, then one way or another we have to get them to trust us'.

"Fantastic!" tries, however, to instill euphoria in the gnomes the blonde arcane warrior (hoping that they prefer to focus on euphoria rather than logic) "See, my lucky guards? Do you even have two methods to choose from! Which one do you prefer then? Your idea or Jasper's?"

Khessa can go ahead and make a Persuasion roll with Katarina's Help.

Lol! As usual, chatty Khessa put herself in a situation where she must leverage her sooooo high charisma skills! Well, let's hope for luck: 18

(Thanks Katarina for the help... and Tymora for the luck! 😀)

(Let's hope that the gnomes are willing to take our willingness to undergo a test that would hurt us as sufficient evidence that we're not shape-changers lol).

Katarina helpfully adds in her two cents:

"Katarina also thinks that it would be most unwise for shape-changers to appear like this... shape-changers would certainly disguise themselves as gnomes instead of appear as elves, humans, and tabaxi, to sneak into a gnome mountain, yes?"

The two gnomes look at each other, then back to you. Finally, they shrug.

"That makes sense to me," says the male gnome.

"Yeah, seems like a lot of effort to shapechange into so many different things," the female gnome muses.

"The workshop is just across the bridge past the spinning blades trap," says the male gnome.

"I almost forgot about the trap," says the female gnome. "We oughtta shut that down for them or they'll be sliced to ribbons!"

The female gnome disappears for a few minutes and then pops out of the corridor to the east. She hurries across the room and gestures for everyone to follow her.

Khessa follows: "Thank you for shutting down the spinning blades trap. Any other hazards we should be aware of?"

"Just the shapechanger that's on the loose!" exclaims the female gnome. "But Fibblestib and Dabbledob will tell you more. I'm sure they would appreciate any help you can provide us in catching the shapechanger that has our King so worried."

You cross the rope bridge, following the female guard gnome, which sways precariously in front of the deafening waterfall. On the other side you see another cave entrance. This cave is lightly obscured by mist from the waterfall. The larger eastern part of the room contains two rapidly spinning devices that look like turnstiles fitted with stacks of long, sharp blades spaced 1 foot apart. The northern turnstile spins counterclockwise, while the southern one spins clockwise.

Set into the south wall of the smaller western part of the room is a brass lever in the down position. The female gnome casts Mage Hand and uses the spectral hand to pull the lever up. The spinning blades abruptly stop.

"There ya go!" she says. "The workshop is just on the other side of this cave. I've got to get back to my post, in case the shapechanger heads our way."

"Of course!" assures Khessa "We will be happy to help you! In this hour of great need, with a shapechangers and a dragon on the loose, we must all be ready to help each other as best we can! We can't wait to meet Fibblestib and Dabbledob".

Jasper looks at the rope bridge to see if it’s safe to cross. If it’s strong enough to hold our weight. Jasper grips the ropes tight as the bridge sways. Reaching the other side, taking a huge breath as if was holding it the whole way across. It would seem the mist from the waterfall wet his face but as he leans against the cave wall, a bead of sweat trickles down the side of his face. Holding his amulet, he closes his eyes and draws out the light of Selune to help calm his nerves. Channeling the Twilight Sanctuary, Jasper strengthens himself and all of his companions.

(OOC: I’ll roll the temp hit points in our campaign chat thread.) 9 temp hit points for Katarina, Aura and Echo. 8 for Khessa. 

Khessa turns a moment to the elf cleric, feeling his holy power bless her: "Thank you so much, dear!" she smiles; then she notices how the other seems... shaken? "Are you ok, Jasper?" she comes near, putting her hands on his shoulders, a little worry in her blue eyes "Are you detecting a threat?"

”Oh! Uh…just a little shaky on that high bridge.” Clears his throat a little and smiles at Khessa. “But I’m alright now. Thank you.” 
As the twilight fades, he says. “I hope this helps. If we take a short rest, I think I can draw upon it again. Maybe after we speak to the gnomes?”

Watching the initially tense exchange, Echo pipes up, "oh man, I thought shapechangers were just scary stories... Did these shapchangers make the king sick? Or is he just worried sick?" She follows everyone over the bridge, giggling as it sways under their feet.

Wondering out loud, "they sure have a lot of really cool contraptions here... and this isn't even the workshop! But at the same time I guess it also makes the shapechangers more worrying," She scrunches her faces up in thought, "do they only change into gnomes? Do you think there might be a shapechanging wall- or chair, table- around here? If that's it, I get it if the King worried himself sick over this."

(ooc: thanks for the temp hp!!)

"Good point Echo..." reflects Khessa, whose experience about shapechangers is practically non-existing "Who knows to what extent they can change their shape... Well," she jokes "the bridge at least did not change under our feet during the cross! We must definitely help the gnomes with this problem".

Katarina walks across the rickety bridge with the grace of... well... a cat.

"Shape-shifters... makes one rather paranoid, yes?" the feline muses, glancing down at the chasm below the bridge. "Katarina hopes that gnome Fibblestib and gnome Dabbledob can tell more. But Katarina wonders... what power is it that elf Jasper can use to make the shape-changers show themselves true? Such a power sounds perfect for the problem at hand. Almost as if fated we were to come here."

Quote from Mister_Whisker >>

Katarina walks across the rickety bridge with the grace of... well... a cat.

"Shape-shifters... makes one rather paranoid, yes?" the feline muses, glancing down at the chasm below the bridge. "Katarina hopes that gnome Fibblestib and gnome Dabbledob can tell more. But Katarina wonders... what power is it that elf Jasper can use to make the shape-changers show themselves true? Such a power sounds perfect for the problem at hand. Almost as if fated we were to come here."

"The point is that Jasper definitely is a gift from fate" Khessa smiles in a sweet and enigmatic way.

Jasper slings his shield and spear over his left shoulder and pulls out a small pouch. He takes one of his moonstones from his prayer pouch and puts it in the small pouch. Ties the small pouch to the amulet chain. 
“Everyone ready?” Jasper looking at the group, lingering on Khessa with cheeks getting red. 

"Katarina was born ready," the cat says with a grin.