"The city square. The execution setup is there."
He's right, at least about the square. You seem to be heading towards the center of the city, and there's no small number of people watching and following at this point.
You seem to have made quite a spectacle of yourselves.

"Are you suggesting I drink on the job?"
You shrug. Only polite to offer.
You then quickly chug half the bottle of grog, eliciting a strange look from the Rhino. You then look around the square as you enter it.
At the center is a large raised white stone platform, looking out of place in the grey cobblestone square. Standing a bit behind it is someone who looks very important. He has long white and gold robes, and looks like he's 80 years old. The man is tall and gangly, and his face is sagging and tired, but he wears a look of grim resolution and iron will.
Flanking him are four humanoids with similar, though less flamboyant, robes, and carrying ceremonial looking flared-headed spears. Notably, they all have dark-green feathered eagle heads, rather than human heads.

All around the square are people, gathered to watch the event. Keeping the peace and ready to interfere are Seekers, a few Guardsmen, and several other types of animals you don't recognize.
"Talkative one. My name is Gen. I do not envy your chances of survival, but it has been pleasant speaking with you."
The Guardsman, Gen, approaches the platform, and sets all 6 of you down on it. Seekers take up positions all around you, while the Guardsman stands next to the girl, off to the front a bit. The old man steps forward, along with his guards, and slowly makes his way up to the platform. The stairs aren't steep or big, but he IS pretty decrepit looking, and it takes a while. Eventually, he reaches the top, and hobbles over towards the girl.

"Sera Maribelle Titania. You are hereby formally charged with threatening the safety and integrity of the Great Sky. Though unusual, the council has determined that due to the threat you pose, your punishment must be Execution."
He then goes into a strange chanting, possibly a long prayer. Most of the crowd joins in as well; seems to be part of the ceremony. Several times during the chanting, Sera tries to edge away, but Gen nudges her back each time. Eventually, he finishes the chant, and the entire square goes dead silent.

"Do you have any last words?"

I do hope this is a magical execution.

If only for the entertainment of that backfiring.

Nah. That'd be a hilarious bureaucratic failure, but nah. They know full well to not use magic after what happened last time.
That's why they've got the Guardsmen! They're inherently unmagical! Just strong rhino dudes.

"Thanks Gen. You seem pretty swell too."

Interrupt the ceremony.
"Hey, quick question. Are we going to be executed as well? Cause it's pretty important to me."

If he says we're not gunna die, then step back and watch. If he gives me any answer that isn't an affirmative, finish my grog and give Sera a nice big hug goodbye.
"Sorry folks, but I'm not dying today. Gen, I hope to god I don't kill you with this. I'd recommend stepping back. This might get messy."

Alright Maarten and Miggles, if you've gotta sling spells, do it as close to Sera as you can. We're trying to get out of here alive somehow, and find our ship. We'll figure out how to make it work if we find it.