There is visible commotion between the three figures in southern chamber, not as the third silhouette emerged from the back it is clear that this one is bigger than gnomes (medium size) and you think one of them shouted at your direction but it is hard to tell with loud waterfall roaring.

Not very long after the potential sound of a something from the southern hall, a tall, lanky, surprising scrawny, half orc dressed in a leather vest and pants  jump out from the hallway from that direction facing towards Goraseth. With unusually blueish tones to his skin, and a large scar on his face around his left eye, he points athe raiper in his hand toward Goraseth, back to the others. "Ah Ha! So you thought you could out sneak Progo did you, change-thing. You will have to try harder then that." He turns behind him and looks at the other two and softens his stance. In a more normal conversation tone he looks back down the hallway which he came. "You know Progo not so sure this is a change-thing. Progo never heard of change-things being able to be multiple looking things at once, especially that far apart." He looks at the the human, "You aren't a change-thing are you?"

Hearing the noise that he made. Goraseth stops: « There’s no need to be stealthy, my friends. We are here to ask for help. ». Goraseth steps in the light so that the gnomes can see him but trying to keep his body covered by the wall and his shield.

 « Hello! I am not a change-thing but a dragonborn, The famous Silver Blade - the best gladiator of the Chult Island. Are you with Fibblestib and Dabbledob ? We’ve been told to enter and seek for them. We are on duty for the town of Phandelin and we would like to talk to the gnome's leader »

Goraseth pauses.... "What is a change-thing?"

"Ahh... yes the famous Silver Blade, how did I not recognize you, ah before." Clearly a fake smile, closer to a grimace, on his face.Bit then perks up "I am the notorious Progo. Here with ah, Pog and ... Progo don't think Progo knows your name."

Hearing the question about the chang-thing He turns back ahalf talking with his hands, "You know the type, today human with mustache, tomorrow gnome with a peg leg. Those change-things. Can't just be themselves." He gets a confused expression on his face. "Must be sad? No wonder they want to be like Progo or ... Silver Blade."

Tryn, a slender halfling clad in simple commoners' clothes, jumps at Progo’s sudden appearance, “What the …?”, but quickly assumes a defensive stance, eyeing each and every move of Progo’s. He chimes in to Goraseth’s explanation, “Yes, as my friend says, we are here to look for the gnomes’ leaders and one gnome we met outside suggested we enter these caverns to look for them. You’ve been with the gnomes that way?” He points south. “Are they sane?” He asks and glances into the northern room, “Just when we entered, we’ve got shot at by a gnome that seemed a bit - how to say? -  with their mind away with the fairies if you catch my meaning. They nearly killed us with their crossbow contraption!” He forces himself to calm down again, “My name is Tryncarin Teafoot, a calligrapher by trade, but scholar by heart. Currently, employed by Phandalin’s town master to carry messages, though, until I have enough coin to set up shop. We’re really not a threat and certainly no change-things.” 

Two gnomes that are behind Progo introduces themself:

I am Pog and this is Ulla, as it seems that you are not shapechangers, and are apparently already invited, welcome to Gnomegarde. You will find Fibblestib and Dabbledob if you cross the bridge, and they will be in the next chamber behind the whirling blades. Watch out for the blades, the switch is on the southern wall. But before you proceed you mentioned clashing with Factorè in the crossbow room, is she ok ?

"Ehm, .... you know.... I will go check on her. I am sure she is fine...." Tharanau slinks back into the hallway towards the contraption room. "Tharanau, by the way!" He shouts back to the group. 

Tharanau quickly walks back into the room with the female gnome. He tries to make eye contact, places his hand on his heart and makes a bowing gesture. "Factorè, I am sorry. I hope you are ok." He bends his head. 
Then he slowly unties the gnome. Holding up the hands and walking backwards out of the room, Tharanau will return to the group and do a sort of awkward thumbs up sign.

"Very well, since everything is in order, we might as well go meet these leaders. Progo, do you want to show us the way  and explain to us a bit more what is this story about shapechangers ?".

Progo seems to give a look of recognition at the name of Phandalin’s town master. "Funny you mention about the leaders here. Progo is here to talk to them too. Progo assumes you saw the posting on the board as well." Noting the blood on Goraseth, "Progo sees her aim is improving with that contraption. Anyways Progo will default to Pog and Ulla for tour guides as Progo only know way to interigation chair down the hall. Didn't one of you mention you've already had troublesome dealing with this change-thing?"

“Yes, that’s right, Progo. We also came here because of the job board. Looks like you beat us to it. Did you already talk to them?”

"Progo has not and has only just proven innocence of not being a change-thing. Progo's assistance was asked in catching intruding change-things which Progo was going to use as act of good will to meet leaders. But then we caught you instead, so not yet but Progo will soon!" The proud confident look on his face slips a little, "compare to the other job I tried before this one, this has been great success. Haven't been chased by flying cat yet!"

Progo sheaths his raiper and stands up straight. "So about these gracious leaders, any chance we talk to them preparing for a dragon?"

“So the gnomes are afraid of shapeshifters?” Wonders Tryn out loud. “Well, let’s go to these leaders and see how things develop,” he states and starts walking towards the gnomes and beyond to cross the bridge, all the time with shy glances to all sides to get a better idea about what his place.

You are leaving the cavern and see before you majestic sight of roaring waterfall plunging into the water below the bridge. It creates a beautiful and dense fog that obscures the bridge. The bridge itself is firmly anchored on the ledges but does sag a little in the middle. The passing is little slow as the whole bridge is rocking a little as you cross, but the whole exprience seem somewhat magical in those circumstances. 

After passing the bridge you enter the chamber with aforementioned 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. The whole chamber is filled with fog that spills in here from the waterfall making it lightly obscured. Remembering the information for Ulla and Pog about a switch you look around and see set into the south wall of the smaller western part of the room is a brass lever in the down position.

"Hummmm, so the lever is behind those deadly spinners...I'm not really keen to try to go through, I still feel the giant bolt that pierced my abdomen."
He turns to his camarades:  "Any ideas ? I mean we could go ask the gnomes how they go through... Tharanau can you teleport in any way ?".

"Nope, Seth, can't do that." Tharanau scratches his head. 
Then moves his hands around and ejects something at the lever that looks like a chain of lightning. With quick and  agile hands Tharanau throws his hands upwards as the lightning connects with the lever and hopes to pull it upward with this swift movement. 
[casting lightning lure in the hope it would work in a situation like this]

"I'm the smallest and I can try to pass by these wheels. In the monastery in which I've served before becoming an apprentice to Gideon Levens, we had practice rooms similar to this. These here look more vicious and, don't get me wrong, I don't relish the idea. If you have better ideas, please, speak up. Otherwise I can try to reach the lever." Tryn checks the room carefully for small spaces that he could use to have a break, spaces that he could use to wait out a turn and catch his breadth. Additionally, he tries to memorise and internalise the rotation pattern, tapping slowly with his left hand on his leg for each full turn of the first wheel and with his right hand for each turn of the second wheel. Does he feel that there is a chance to get through these unharmed? "Could we, maybe, block the apparatus with something bulky?"

« I guess I could throw a rope in lasso and try to block one meat mincer by force »

"Progo wonders, how would gnomes pass? If they turn the spinners on by that button when they are on that side, wouldn't they need a way to turn these off to pass? Progo thinks the easiest way would be to have someone over there to click button. Maybe we simply call for a guard to turn it off. Progo doubt gnomes lasso their way through here. Beside we might not be in very good standings if we disable all the gnomes defenses..."

"Yeah, you're right, Progo, " Tryn concedes, "They probably have someone there who they can call upon to switch it off. Only when we found the caves and called out to the gnomes, one very irritated gnome spoke to us and warned us that they all are trying to sleep and that we shouldn't disturb. I fear that the same gnome is responsible for the mechanism, or another one that is sleeping. We might be unable to wake them up from here, or upset them more in the process. Perhaps best we go back and ask for assistance." Tryn turns back to the bridge and crosses to confront the two guards there. "Oy, friends. How can we pass through these blades? The lever you mention is on the other side and we don't arrive there in one piece while the machine works. How do you cross from this side?"

" What? You have not crossed yet? Of course it is on the other side, otherwise that would not be much of a defense mechanism. Normally i doubt you would even see that lever in all that mist over there, that is why we told you about that. I really hope you have some other talents if you are to prove useful for us. Pog would you mind help our guests?" -says Ulla

Pog just nods and goes with you to the room, puts his hands up, closes his palm and opens again dynamically and says a magic word. With that, spectral hand appears just by the lever and pulls it up. Then turns around and leaves saying to you: "Turn it on again when you pass".

/Lighting lure would not work, first out of the nature of the spell, and second because of the range as switch is about 30 feet from where you can stand in front of blades/

Traversing for the next chamber you expect it to be the one with people you should talk to. Walking in you overhear a conversation understandable only for those who know Gnomish, everyone else can distinguish from that only the names Fibblestib and Dabbledob that you have heard before and you are supposed to talk with the gnomes of that names.

(what is conversation about in the spoiler for gnomish speakers)

 The workshop is cluttered with half-completed gnomish inventions that serve no purpose, as well as worktables strewn with tinker’s tools. A 10-foot-high ledge overlooks the room, set with a wooden pedestal on which sits a leather-bound book.