Kili didn't understand why they were jailed. They hadn't stolen anything, why should they be punished for wandering through a forest? Did the elves own such a horrible part of Middle Earth? Disheartened, he kept by the door of his cell, keeping an ear out for his uncle. Thorin had not been taken to the cells. "How long will they keep us here?" Kili looked to Saeril, hopeful that she may have an answer. 

Unfortunately, Saeril was lead away by a guard on either side. 
"Wait! Where are you taking her?!" Kili demanded to know, only to be ignored. The guards lead his godmother away, and Kili found himself alone with only the sounds of Dwalin and the others arguing among themselves. Fili must have been jailed further down the row.

King Thranduil had risen from his impressively carved throne, his gray blue eyes settled upon Thorin. 
“Some may imagine that a noble quest is at hand. A quest to reclaim a homeland and slay a dragon. I myself suspect a more prosaic motive: attempted burglary, or something of that ilk..."

Though seething with hatred, Thorin remained in his place, even as the elven king invaded his personal space. 

“You have found a way in. You seek that which would bestow upon you the right to rule: the King’s Jewel, the Arkenstone. It is precious to you beyond measure. I understand that..." Thranduil took notice of Saeril now, and then he looked back to Thorin in hopes for a response to his proposition. "There are gems in the mountain that I too desire. White gems of pure starlight. I offer you my help...I will let you go, if you but return what is mine.”

Thorin turned slowly, then walked away. "A favor for a favor."

“You have my word." Thranduil promised. "One king to another.”

Thorin stopped. Still facing away from Thranduil, he spoke, his voice raising with every word.
“I would not trust Thranduil, the great king, to honor his word should the end of all days be upon us!” At this point, Thorin was shouting.  “You lack all honor! I’ve seen how you treat your friends. We came to you once, starving, homeless, seeking your help, but you turned your back. You turned away from the suffering of my people and the inferno that destroyed us! Imrid amrad ursul! (Die a death of flames!)"

Thranduil's eyes widened, and he moved forward, bending down slightly so that his face was level with Thorin's.
“Do not talk to me of dragon fire. I [i]know[/i] its wrath and ruin. I have faced the great serpents of the north!” As he spoke, his face contorted, revealing horrible scars and burns on one half of his face. One eye was milky in color, indicating that he may have been blind from it. After this, he pulled away, his face returning to the illusion of normality.
“I warned your grandfather of what his greed would summon, but he would not listen. You are just like him.”

Thranduil motioned for the guards, and they grabbed Thorin roughly by each shoulder. “Stay here if you will, and rot. A hundred years is a mere blink in the life of an elf. I am patient. I can wait.”