After her companions goes back inside the keep. "If you will excuse me for a moment Ms. Harpell." Kazri address Vellynne, she then sits on the courtyard floor cross legged in front of Oli. She give the owlbear a big hug, and tell him that she is sorry for not spending more time with him, and that she is very proud of him. "I am sure that your uncles are also very proud of you as well."

Up the stairs the party went, Chill in the lead scouting ahead.  You head down a hallway and enter the door on the right.

A chilly draft wafts through this bedroom despite a roaring fire in the hearth. Bundled under a thick quilt and seated in a squat rocking chair in front of the fire is a venerable dwarf with a wooden peg where her right foot should be. Next to her, on a small table, is a plate of food. Her eyes are closed and a quick inspection reveals that she is not breathing.  If she has passed, it was certainly very recent.

A check of the rest of the room reveal that they are all unoccupied.  

The room across the hallway (C12)

A large, gilded mirror covering most of the east wall. Other furnishings include an ornately carved wooden table and chair.

The other side of the upstairs

C14

This room is immaculately furnished. It has all the trappings of a royal bedchamber, including a soft bed, warm quilts, elegant tapestries, and a gilded chamber pot. Bars over the windows dispel the air of luxury somewhat.  Your guess is that this is the speaker's bedroom.

C15

This room looks like it suffered from a fire, likely years ago and never repaired. Evidence remains of floor-to-ceiling shelves along the walls. A draft issues from a darkened fireplace, stirring the cobwebs around it.

No one else is found in the castle keep.

Krom examines the dead dwarf attempting to determine the cause of death. "Her death seems to be very recent, I wonder if she was a cultist herself or a member of the Speaker's staff. Tomorrow, before putting her to a proper rest, I'll try to contact her spirit. We may gain further insight on the cult."

Medicine 6 + Guidance 3

In spite of knowing the futility of the effort, Rhogar makes a tugging motion at his chest, drawing forth a mote of light that appeared to crackle like a ball of electricity, then sends it to the dwarf to try and revive her. "Could be either or sadly, or someone unrelated at all, as unlikely as -that- can be. Either way, may we find out tomorrow and hope her spirit minds not overly much the disturbance. But let's leave her there until we've completed our survey." Rhogar asserts, though with some measure of reluctance. And despite his own words, he found himself lingering for a few moments longer seeming thoughtful for a time, before finally drawing forth a familiar wand and giving it the old scholar's try. If afterwards he detects no magical -- residual or otherwise -- over the dwarf, he'd suck in a sharp through the nose, and stiffly moved on from the area with the magic still active.

When all is said and done in regards to the search, Rhogar offers to bring the dwarfess downstairs to be at least be properly tended to by the servants. But otherwise apart from informing the Speaker and staff of the end of the search, the dragonborn eventually broaches the topic of what was to become of the cultist(with hopefully the party fully gathered by then or as much they can be).

Chill moves smoothly through the rooms and in short order finds them all empty, except for the deceased dwarf.  He leaves the examination of the dwarf to Krom and Rhogar who were far more qualified for the work than he.

He heads back down and informs the speaker and Kazri of their findings. He knew better than to plunder the castle, anything found was the speakers and the people's.   But he was certain the items found in the cistern belonged to whoever left flying over the wall in such a hurry.

When given the chance he'll see if Krom could identify them. 

Krom can't be very certain about much regarding the death of the dwarf, except that it does seem recent and there are no obvious wounds on her.  She does look very old.

Rhogar uses his wand to detect magic but the power of the wand reveals nothing to him.

With the castle cleared the speaker is safe to come out of his room.  Kadroth eventually awakens and glares at you but his bindings do not allow him to take any vengeance against you.

The speaker sends one of his servants into to town to find some village soldiers to help secure the castle walls while he decides what to do.

You gather in the main hall.

"This Kadroth was the worst of the lot and their leader.  I would see him hanging from the walls as a warning.  As for these others, I do not wish for their blood on my hands.  Justice upon there leader is enough for me.  Let the others go as long as the promise to leave Caer-Dineval and never return." the speaker says in his judgment on the remaining cultists

A short time later, the servant returns with a few men to help guard the castle.  They also report that the cultists who were guarding the body of the dragon have fled the town.  The body of the dragon is unguarded and any cultists in town seem to have left according to those who come to act as guards for the castle.  

Krom keeping Kadroth and the other cultists always within his sight, listens as speaker talks "As Speaker of Caer-Dineval, it is your right to dispense justice as you see fit. Kadroth, for what he had done deserves a severe punishment indeed, but before dealing justice I would like to know what they were trying to attempt here. There is a shrine to an archdevil in the cistern and that tiefling wizard fled the castle before we could apprehend her. She may be the real mastermind behind what occurred here."
The dwarf turns towards Runa and the other cultists "Some of those, Speaker, were already given a second chance" his gaze fixes on Runa "but it seems to me that they have used it for the wrong reasons."

"On that note, I would have to agree with Master Krom. We have -- beyond any interrogation tactics -- a bit of magic aught to help in the process to employ... again with your permission of course, Speaker." Rhogar  bows his a head just a bit in deference, before fishing out a potion bottle and waving it by way of some explanation. "For with the amount that have already slipped the noose as it were, and plans to release more, some...  may yet readily rally to her side. At which point there's no telling what other mischief they may yet get up to. Be it elsewhere in the remaining Ten Towns or the dales at large. Especially with this archdevil worshiping they got up to.... I... Believe there was a kid as well that recently came under their sway we were to find? Or was he led to a different Caer?" The dragonborn added, only to trail off towards the end massaging his throat absentmindedly in thought.

Kazri leaves Oli in the courtyard, and goes to join the others. She arrives just as they are speaking with Runa. She unsheathe her sword, and she stands on front of female warrior. "This is your last chance Runa."

(sorry, Holiday weekend in the US and I was super busy)

The speaker furrows his brows.  "I do not wish for further bloodshed.  You are free to interrogate the prisoners as you see fit before justice is taken against the leader.  The others are free to go, as I have said, when you are done with them unless you have your own reasons for justice against them.  My understanding is they did fight against the dragon and helped keep it from destroying the town even though you did most of the work in that means.  For that you surely are owed gratitude." 

He continues

"What kind of cult they are and who this archdevil is I do not know.  I do not know who this tielfling wizard is either."

At the mention of the tiefling wizard Vellynne takes note.  She quietly speaks to Kazri "A Tielfing wizard? Did she have a crow with her by chance? I may know who she is."

Kazri thinks for a moment. (She was slightly busy trying to avoid folks trying to kill her, and arrows directed at her) "To tell you the truth, I didn't have a good look at the person, but I do believe a black bird did follow her. Perhaps it is the same person."

(In case anyone needs a refresher. Post #3259)

 "Things were not quite that way, Speaker. But-..." Rhogar side-eyes the cultist. "Many stood at the walls ready to defend this place, at the very least. And they had at least offered some sanctuary to those citizen willing to take it prior to the crisis... had they at least overcame their apparently well deserved misgivings. And once it defeated, they did do what they could to assist, if only for appearance sake."

The Dragonborn then focuses his gaze on the speaker, and with only a hint of relunctance bowed his head slightly in deference. "Either way, your word is law here, and we shall respect it. Our grievences are but a minor thing in comparison to any you and your staff may yet have for these despicable miscreants. But-..." At this point Rhogar turns fully to the cultist and even approached within ten feet of them. "Let it be made clear. Beyond Ten Towns and whatever mercies those in charge may yet grant you, IF any of you do not take this chance in exile from this place as one to make amends elsewhere, OR seek vengeance again beyond the 'safety' of the Ten Towns, I will show you no mercy. A warning and a promise, not a threat."  He stares at the group for a long, hard moment, then lets out a huff through his nose rich with the smell of ozone.

"... Now let's get this interrogation over with. Master Krom. Chill. If you would like start things off." He states more than ask, but trusted the pair to understand a moment was needed for him to cool off. In the meantime, he'd finally down his potion and for the first few seconds rely on its surface reading abilities where it pertained to Kadoth as others questioned the tiefling.

(@Wolfy: Refresher certainly helped.)

Krom nods at Rhogar as the dragonborn clarifies the extent of the cultists involvement during the fight with the dragon and the aftermath. "Speaker, forgive me if I am a bit blunt, but as Rhogar said, they mainly stood on walls with their bows at the ready, only to defend themselves, not the population of your town." adds the dwarf.

As the dragonborn finishes to address the cultists, Krom taps the floor with his warhammer making a loud metallic sound then asks Kadoth and the rest of the cultists. "What is that you were here after? What is the meaning of that effige of Levistus? Is the archdevil lending his strength to the Frostmaiden so that she can keep this endless winter forever?" says the dwarf in a firm tone.

Chill stands next to Krom and idly draws a dagger and starts to sharpen one of his claws with it. He says nothing to start but watchs the reactions of those being questioned and tries to gauge their honesty in answering any questions.

Insight 11 (passive is 18)

Meanwhile Kazri goes to Runa. "Do you have anything to day? You can still be a force for good, or you can join their lot." Kazri nods to the cultists.

Kadroth eyes flared in anger.  "We are here to save Icewind Dale from a duergar threat, they plan the destruction of the Ten-Towns.  That dragon may have been part of the plot.  We are doing our part here.  That threat is still out there and no we will not be able to help.  You have weakened Icewind Dale by your actions this day. We are no more a cult than any other religion in the Sword Coast or beyond." he says in answer to Krom's question.  His tone is haughty and in defiance to you. "As for the Frostmaiden? We have no such allegiance to her."

Chill

 Rhogar

Runa sneers at Kazri. "Do as your god will allow you if dare strike me down in cold blood. But the dice of my life have already been thrown.  I owe Levistus my allegiance and my life.  That will not change for you."

"We took care of the duergar. The remaining ones have returned to their Underdark homes and will not bother Icewind Dale anymore." replies Krom. The dwarf takes a step towards Kadroth and pointing a finger at the cultist says in a firm tone"You worship an archdevil! Do not dare to compare you and your deranged cultists to a proper religion!"
"You were trying to help? By keeping the Speaker prisoner and by murdering his people? Bah! Your actions speak clear Kadroth, you and your group are murderers!"

At some point during Kadroth's vocalized explanation, Rhogar looked away seeming thoughtful for a time, but would soon shake off whatever errant thought grasped his attention following Krom's headed rebuttal. The dragonborn then too steps up and places a a firm hand on dwarf's shoulder, and give not so much as an admonishing look as it was silent plea for temperance if Krom deemed to meet his gaze.

After which, Rhogar looks to Kadoth and asks, "There was another that fled from here capable of flight. I believe they were a tiefling much like yourself, though admittedly there a ways off by the time I reached the walls and saw them fly off. And though it could've just as well have been happenstance, given their capabilities, I believe they possessed a crow familiar as well. What can you tell us of them? Were they not party to your group? Or merely aligned in cause for the moment?" He asked, taking clear pains to project a calm exterior, even though he too seethed beneath the surface. But anger, he'd knew, would cloud the mind and make the task of continuing to read Kadroth's surface thoughts more a challenge then it needed be in the moment.