Gregor took up a job in puzzle maintenance, and mainly worked with Second Rock. Second Rock had a lot of ideas, but lacked the limbs and mobility to execute them. Gregor's ability to crawl on walls came in handy, and with the right tools he could manipulate the fine mechanisms that made puzzles tick. He learned by doing. Second Rock was always willing to patiently explain what needed to be done and how to do it, and as time went on, Gregor needed less and less instruction.

When Second Rock was satisfied with Gregor's knowledge of puzzle machinery, he started involving him in puzzle design. Although it was shaped by the options afforded by the machinery, it was much different. It was more intuitive, harder to make objective. He liked it, but he never felt as confident about it.

The payoff came when he attended the opening of a puzzle he had worked on. He watched a child move boxes this way and that way, sometimes backtracking, until all switches were covered. A bell went off, and the child cheered. Gregor felt his face make an unfamiliar motion. He realized he was smiling.

He wasn't just learning about puzzles - he also learned a few new things about himself. One day, as he was climbing a few meters up a wall, his legs lost their grip and he started to fall down. But he felt something unseal on his back, involuntarily, and before he knew it, he was hovering in the air.

That was how he found out he had wings.

There wasn't much use for them in the cramped catacombs, but he soon made a habit of flying around the city. It had ample accommodations, thanks to the number of flying monsters it housed. Buildings with multiple floors often had balconies as additional entrances. But even if there hadn't been then Gregor would fly, just for the fun of it.

He made small talk with the other monsters he met in the air. They were occasionally surprised by his lack of basic knowledge, but they were pleasant enough.

The queen still met him regularly, to interrogate him about the surface. She was interested in every detail, and made copious notes. She asked him about politics, culture, national borders, language, and any and all myths that may involve monsters. Even when Gregor was uncertain (which was often) she would write down his best guess.

After a volley of queries during one of the sessions, she switched the subject. "What do you know about the layout of the underground?"

"I know my way around Home," he replied.

She smiled. "Mount Ebott is rather larger than that. We have crammed ourselves here in the back, but a vast stretch of space to the East is unoccupied, all the way up to the largest exit. It may seem silly to you, with your first-hand knowledge, but we were still afraid that the humans would at some point follow behind us and - finish the job."

"You're still hiding?"

"We are. You must have picked up on the general attitude towards humans. Children still scare each other with tales about your species."

"But after all that time?"

"We did not know that we had been forgotten. Even if no humans had any intention of attacking us, we could not be sure that none would in the future. But if nobody remembers our existence then it should be safe to move to the wider caves."

Gregor was somewhat shocked by this. He understood how his knowledge would be interesting to someone sealed underground for thousands of years, but he hadn't understood it was this useful - not just satisfying intellectual curiosity, but leading to monumental change. The trust she put in him was astounding.

"I plan to make the announcement tomorrow morning, with my husband. Please do not tell anyone until then."

The news must have spread quickly. Second Rock already knew when Gregor met him the next day, even though he rarely left the Ruins.

"Did you hear?" he asked.

"I did," answered Gregor.

"Many opportunities. There's ice out there. And water. Lots of potential."

Gregor didn't need to ask what he was talking about. "Are you going?"

"No. I belong here. You should go."

"Do you think so?"

"Yes! It's all empty now. It needs puzzles. It needs you."

He considered the idea over the next several days, and decided he agreed. He liked the underground and wanted to see more of it.

He rarely thought about the surface any more.

Gregor was finally home.