As the others meet up Chill finds the next room is unlocked.  With Gorrah on his shoulder he enters the room and closes it behind him.

A fireplace, with a warm fire, is on the left wall.  On the far wall is a large desk.  A bookshelf is on the right wall. There are no other doors although Chill's very perceptive eyes note what is likely a secret door next to the fireplace. 

Sitting at the desk is a pale human man who looks to be about 50 years of age.   He wears frumpled clothing and has a harried look on his face.  Behind him stands another man, with an amulet hanging from his neck.  He sneers at you.

"Eh! who are you and where is Kadroth?"  He says in a demanding voice.  "Come any closer and I kill this man!"

(Sorry folks. Posted this while DM was also posting. Didn't realize above post til now.)

(Basically Kazri thinks that you guys have things under control, and she will make sure we are not surprised from behind.)

Kazri nods at Krom. She stands by the door looking at the entrance's double door. In case any problem comes their way. Shield and sword ready.

Chill didn't hesitate,  he was certain who was who in this room and the threat was enough for him.

With a flash a dagger was sent towards the man standing making the threats. 

BA Steady Aim

Attack: 24 Damage: Unable to parse dice roll.

The dagger sunk into the chest of the man who then fell to the floor dead.

The other sitting at the desk suddenly stood, the fear in his face replaced with gratitude. 

"Oh thank you!" He exclaimed.  "Have you come to save me?"  He then pauses and seems to regain some composure. "Who are you?  I am Speaker Crannoc Siever.  Where is Kadroth, is he dead?"

In answer to the Speaker's question, Gorrah tries to project in his mind the image of Kadoth with cartoon stars for eyes, followed by feelings of contentment. Although she's quickly put off if unable to establish even a brief connection for such, she just as quickly loses interest and glides on over to the fallen man with every intention of biting his nose and making sure he was dead-dead.

It's mayhaps around this point Rhogar is not only answering Krom, but directing the dwarf to follow after sparing Kazri one last worried look. "Well done, Master Krom. But as for the Speaker, they-..." He pauses, seeming startled by something, and then breathes a sigh of relief. "It seems Chill has seen to their safety as well in the other room from what Gorrah has seen. Come, come." With that, Rhogar with his package still slung over his shoulder would make his way into next room with Chill and the others.

"He's not dead. Not yet, at least. But he may wish it before the day is out." Rhogar answers as he enters the room with a wary, toothless smile. "Greetings, Speaker. Apologies for the rather boorish introductions. Yet as you're no doubt aware, your keepers were rather keen on playing coy about things, to say the least. The name is Rhogar of Clan Nimbatuul."

"I'm glad to hear that Rhogar." nods the Dragonborn informs him that the Speaker has been found. "Let's hurry to his side." the dwarf follows Rhogar as he guides him into the next room.

After Rhogar's introduction, Krom takes a few steps towards the speaker "I am Krom Firebeard, Smith of Moradin, member of the Fellowship of the White Cloaks like my companions here. Do you require healing of any sort?" says taking a good look at the Speaker. "We were told that you were ill. I have used some of Moradin's blessings to despatch the cultists outside, but I can still invoke the All Father to heal any ailments caused by Kadroth and his knights."

Sensing that everything is under control, Kazri raises her shield and goes to the double doors to check on the situation outside. "Master Krom, I will check on the situation outside of the keep." She will also check if Runa is still wrapped in her Nature's Wrath.

Perception: 8

"Why yes Speaker, we have in fact come to save you.  I am Chill, a member of the Fellowship of the White Cloaks.  We understand that you are in some sort of trouble." Chill nods at the dead man and he walks up and pulls his knife from his chest and wipes it off on the man's clothing before slipping it into it's sheath.

"Seems to me these are some sort of cultists you've got yourself wrapped up with."

Hearing the door behind him open he looks over his shoulder.  "Ah yes, my esteemed colleagues, a couple of them at least.  So tell us Speaker, what is exactly going on here?  How many are these cultists? I'm not quite sure the fighting is done just yet."

The look of relief on the speakers face says much.  He quickly tells you his story.

"Several weeks ago these people arrived under false pretenses, claiming to be neutral arbiters employed by the Council of Speakers to help Caer-Dineval resolve its fishing disputes with Easthaven and Caer-Konig. So I let them in but it quickly turned out they were not who they said they were. These cultists slew the my guards but are keeping my servants alive. I was warned to behave myself lest my servants pay the ultimate price. I don't know where the servants are being held but I know the cook is still making meals. I suspects the rest are being kept in the cistern under the castle.  This Kadroth, he is their leader. He's the one calling the shots but he answers to someone named Levistus.  He kept me under guard and locked in my bedroom.  He lets me out now and then to sign something.  In fact today he dragged me out and told me we had visitors, I assume you, and I was to get you to go away.  All under threat to my own life and those of my servants of course."

He sighs and continues "I've never been the picture of health but Kadroth here has told everyone I am too sick to come out. There is nothing seriously wrong with me, a bit of sickness I suppose. As for how many, I do not know.  Nor do I know what their other plans are or why they wanted the castle."

He looks imploringly at you "Please rid the castle of the rest of them and free my servants.  Justice must be served and the castle set right again."

"Hmm... Well, Kadoth will unconcious for at least an hour thanks to Gorrah over there." Rhogar gestures to the psuedodragon, who in turn looked up from trying to grab the one fallen cultist's necklace, before sitting back on her haunches and wave at the Speaker. "And we'll keep the one on my shoulder about to act as a guide. A little early pentinance for their misdeed. Isn't that right, friend?" Rhogar asks, side-eyeing the cultist hung over his shoulder. 

Without waiting for a reply, the dragonborn continues, "That said, and I hate to suggest this, but do you think you can manage to bar yourself in a room? Not yours, as they'll likely search there first now that things have escalated, but another perhaps?" He asks as much, and upon recieving an answer, nods before letting himself drift off in thought from the present situation to ponder. " Levistus... Levistus... why does the name ring a bell?" He mutters.

(@DM: Not sure what kind of check it would be to recognize the name in game, but here's a flatd20 roll and you can apply the appropriate modifiers if any of Rhogar's skill would suffice, assuming you feel it would be knowledge within his current wheelhouse. 6)

Rhogar can't seem to place the name of Levistus, but Krom certainly can.  

Krom pipes up"Aye, I have heard that name, though know little about him.  Some archdevil in the Nine Hells is what I know, but nothing beyond that."

Kazri cannot see or hear anything beyond the wall of fire which will drop any second now.

"This is the second time we encounter emissaries of the Nine Hells in Icewind Dale. A devil also infiltrated the fortress of the duergar." adds Krom after informing the group of what he knows of Levistus.

"It may be dangerous to keep Kadroth alive, but as we have a castle to clean, for now, leaving him uncouncious will have to suffice. Just to be sure, we should bind his hands and gag him."
The dwarf takes out from his backpack a rope and a couple of bandages then proceeds to fully bind and gag Kadroth with them.

Kazri stands by the double doors ready to stop any "uninvited" guests that might to try to get into the keep. (Is Runa still wrapped in Nature's Wrath?)

"An hour eh?  I bet we can clean this place out within an hour.  But are we running them off or just killing them all?  I suppose there will be some killing but maybe the rest will surrender when they realize we have taken Kadroth out.  Our new friend here can probably help with that." Chill remarks

Rhogar's eyes went a fair bit wide at the news, before grimace and shaking his head in clear disgust. "/If/ they surrender and times afford it, then shall see them captured so that they may stand trial for their misdeeds in whatever way the town deems fit. But such shall be the limit of mercy shown this cretins. So if any choose to run, they better pray they do so long before we see them." With the declaration made, and not knowing how much time they had actually left with Krom's fire trick, Rhogar looks to Gorrah and if only for the Speaker's benefit says aloud, "Guard the speaker, and make sure no further harm comes to him, my sister. And Chill-..."

He turns then to the Tabaxi. "You still have the keys? Good. Lock the room behind us. Though Speaker." Rhogar looks again to the human(?). "Best you bar the door further if you have the strength for it. With any luck, we'll be back shortly -- oh! And also, how might we reach the cistern? Just in case they opt to try and go for the prisoners in hopes of holding them more pointedly hostage." As soon as Rhogar had his answers, Gorrah takes to trying to perch on the Speaker's shoulder as the dragonborn rushed for the main hall ready, if not quick to assist Kazri in dealing with any onrush of enemies.

"Remember that we are dealing with devil worshippers, if too many of them run away, left unchecked, they may attempt once again to sow mischief in the Dales." says Krom as he follows Chill and Rhogar. "But in that case our Fellowship will deal with them once again." adds with a grin the dwarf.
"Anyway, I agree with you Rhogar, we should reach the cistern and free the prisoners as soon as possible."

16

10

Attack: 20 Damage: 6 

Attack: 5 Damage: 10 

Attack: 10 Damage: 11 

Kazri looks down and sees that Runa is still unconscious and bound by the vines.  As she does this the wall of fire that Krom had placed suddenly drops and hail of arrows land around her.  Looking out she sees 3 soldiers still up on the walls firing arrows at her.

On the ground near the area where the wall of fire was several more cultists have gathered.  When the wall of fire falls three of them move forward, scimitars ready and they attack!

Attack: 8 Damage: 9

Attack: 8 Damage: 6

Attack: 18 Damage: 3

Meanwhile inside...

"I can bar myself in this room.  With the door locked I'll be safe enough if you have the keys.  Access to the cistern is through a door in the floor of the north west tower.  There is a passage through this office that will take you there.  I don't think the cultists found it."

As Chill saw earlier but had not fully investigated, a secret passage did run from next to the fireplace.  With the door opened you can see where it leads 20 feet down to another door that would then lead into the guard tower.

"Kazri has not returned yet." says Krom "Even if she is capable of taking care of a few cultists, I'll give her an hand. We will then take the outside route to the north west tower and regroup inside. The door may be locked, if you can Chill, open it for us." finishes the dwarf as he dashes towards Kazri's location.