"I am glad I need not sleep unless I wish to," Karil mentions.

"Right convenient, that. I'd better get back to my borehole."

"Enjoy your borehole?"

"Not for itself, really. Planning for future expansion, you dig it?"

"Yeah. Can other people visit these places?"

Whisper whisper. "I don't mind if you don't get to sparring inside it, but she doesn't want visitors. The entryway I use is mighty uncomfortable for human-sized folk, though. Maybe I get around to widening it eventually."

"Well, if you ever do, and are not uncomfortable with visitors-who-will-definitely-not-spar, I would love to visit."

"You could fit now, it's just most people don't want to bother."

"I am somewhat different than most people."

"Follow me, then. I'll walk for once."

He digs himself out to reveal short legs, clawed feet. The other one starts tunneling away.

She looks at Karil and tilts her head a bit as if asking for permission.

Karil tilts his head in response.

The digger starts walking. 

She follows.

"Name's Baso by the way."

"Sadde," she introduces again, in case he missed it.

He starts rambling about the art and science of tunneling. He walks pretty slow.

She asks questions! Rambles are fun.

So she can learn a fair bit about stone and earth and structures made therewith and drainage and clefting and... 

"Well, here we are. Follow after me." He opens a wood door and starts down a narrow, low, but passable hallway.

She follows! And shrinks her wings back.

It's dark in here.

Baso seems to navigate mostly by smell, he starts pointing out features of the vault. Living room, kitchen, workshop, stores, main vault.

"Because everyone needs a good vault. Haven't traded for much decoration yet though."

She can see in the dark just fine.

"What sorts of things do you trade?"

"Basements, mine 'an quarry 'an cave appraisals, safety reports and so on, various tunnels."

"Makes sense." She looks around, trying to get a feel for the aesthetic and details.

He seems to like rectangles, and tiered structures. Lots of straight lines in sometimes-intricate patterns, lots of little cubbyholes and shortcuts from place to place, ladders and tunnels.

The main vault isn't much smaller than some famous cathedrals back on Earth, they even have a few topside windows letting moonlight through. The walls are relatively bare as he said and the far side marks it as a work in progress as about halfway up another meter or so is dug out.

"This is really cool."

Smile. "Thank you very much. Some folk have said this already that we diggers have grand designs, but this feels downright cozy to me still."