I made some historical research (zero findings) and fiddled with dfhack to get some info... Without further ado:
Atu let out sting of death curses and tried to slash at the cage bars - to no avail. In spite of being wooden, they were thicker than her leg and damn cage had no place for taking a proper swing at all. Dwarf that was hauling her somewhere shook the cage while shouting some words in a low, angry voice. Something along the lines of 'stay silent, else I'll turn damn cage upside down', no surprise here.
Atu was pretty sure that she would be dumped into a pond full of cave crocodiles or into magma pipe and prepared to take a last dash for freedom, but dwarf simply put the cage in the corner of a large, finely-smoothed chamber and left, grumbling under his breath.
Not really wanting to take chances - of all she knew, her captors could be preparing to flood this room - Atu gnawed on wooden bars, trying hard to suppress the pain. After two minutes of work, blooded wood showed signs of her frenzied gnawing, but it would need much more to fall apart... Actually, too much for her sore teeth. Then, her eyes fell on an iron longsword she still hold in the right hand.
"God-fucking-forgotten-dammit!!!"
"Che. You're too noisy."
"Who is here?! Show yourself!"
"Oh, and dumb. Atu, use you brain. Though it seems you don't have one..."
"Strodno! You little..."
A conversation was cut short as another cage with grim-looking Ngebzo was situated across the room.
"Ngebzo, you too?!"
"Congratulations."
Spearman did not respond, mumbling something to himself and Atu returned to disrupted talk:
"What the hell has happened here? When gates opened all of us thought that you three got dwarves... Er... Where's Beya?"
"Dead."
"Bloodkin?.."
"Try to guess."
"So, their army subjugated you after assault failed?"
"Eh? No, nothing like that. Seriously, I killed their whole military and hunted civilians for three hours straight."
"... And then?"
"I got bored."
"What?!"
A fourth cage, with Song tightly clutching her warhammer, was put into the last corner. Dwarves - now three of them - started arguing between themselves, but soon left. And Strodno continued, as if nothing happened:
"So, as I was killing civilians right and left, I got tired and walked right into the trap..."
"Pathetic!"
"Let me check if you're saying this from behind the bars?"
Atu growled and punched the unmoving cage several times. Then, she had an idea.
"Lord Utes army would save us, right?"
While Strondno only gave an amused chuckle, Song signed and cited in high-pitched voice:
"There's no room for mercy in this world!"
Ngebzo coughed and agreed:
"Do not serve blindly. All know that Utes Bonenightmares the Beloved Polish only cares for his underlings as long as he needs them."
"For all we know, he can leave us in cages for his own amusement..."
Atu grew silent, trying to process new information. She never gave a second thought about this.
With a sound click, hidden mechanisms unlocked the cages and let goblins free. Atu smashed the bars aside and rushed back to the entrance to repay dwarves for humiliation - only to find a smooth wall in her way.
"What?!"
Ngebzo came closer and thrusted his spear several times into the wall, chipping small bits of stone.
"Figures. They don't have enough manpower to deal with us. And no pet cave crocodiles, either. They settled upon best way of containing us."
"And so, we're doomed."
Song was optimistic, as always. But her statement wasn't far from truth.
"All right. We have four cages, some stone, useless mechanisms, a dwarven arm - thanks, Song - several dice and my collection of dwarven teeth. Everything right?"
Strondo naturally took a position of leader, not only as a best warrior and dwarf killer, but also as an only capable candidate. She was patient and level-headed, in strike comparison to ambitious Atu. Who also could not complain of being the best thinker around. Ngebzo, on other hand, was quite smart, yet this came with inability to focus and sub-par fighting skills. Song, the youngest of four, was out of question with her attitude and inability to properly swing her own hammer.
"Good. Then I suggest we play a few rounds of dice before building beds from the cages..."
"Stakes?" - Ngebzo livened up.
"Beds?" - said Atu with unhidden disgust.
"Sleep on the floor, dimwit. As for stakes - teeth, obviously. And we have all walls in this room to keep tabs on debts."
"Sounds good."
"Song, you're in?"
"Y-yeah..."
"Gimme the dice! And let the gods curse your throws!"
Two dwarves stood outside, listening to the muffled guttural cries.
"Bet they're panicking now."
A clash of metal could be heard.
"Or killing each other... It was a great decision to put statues of our military commanders here, so that we would not forget."
Architect nodded, proudly observing his work.
"This wall will hold out until the dawn of times. Every crack inside is checked and smoothened. They have no means of escape."
"Good. Very good. How about a drink?"
"Aye, my pleasure."