"I'm telling you, it was blue. Blue like new overalls right when we first get them. Maybe ever lighter than that." I spun, suspended over the Belly, as I handed Yaneli a wrench. Below us the vastness of the Belly sprawled beneath a haze of smog— pounding engines, pipes blistering hot or freezing cold, wires and metal ladders crisscrossing it all like spider webs. The oldest engineers had told me that generations ago, when the vast, dark clouds cleared, the Belly stretched so far into the distance it seemed there was no end.

Yaneli's voice came out muffled, her body partially concealed in a gap in the broken paneling. "Sounds made-up to me. If it was gonna be a color, it'd be brown. Or gray. Or black."

"It's black at night. When the sun is gone."

"See, that's what I'm telling you. It's probably just black all the time."

I rolled my eyes. If Xyla were here, she would have agreed the sky might have been blue on Old Earth. Some of the oldest engineers told stories about Old Earth, tales they'd heard from their great-grandparents, who'd heard from their great-grandparents, but after so many generations it was difficult to separate truth from fiction.

"Where'd you even get the idea of a blue sky?" Yaneli called back from inside the chute.

"A book."

"And how'd you get this book?" Yaneli's voice sounded funny—probably speaking with a screw held in her mouth.

"In a completely legal, legitimate fashion, of course." I grinned and hung upside down, pretending I was a bat—one of my favorite animals I'd discovered in our illegal stash of Old Earth books. "What do you think I am, a Pucker?"

She poked her head out, eyes narrowed. A couple years ago the guards had rounded up and burned every book in the Belly library, claiming some of them had "dangerous ideas." Yaneli said it was because they were afraid of another Great Uprising, but since they burned anything written about the Beast's Three Great Uprisings, how the hell was I supposed to know or care? All I knew was that burning the public library was both a travesty and a wonderful business opportunity. No one wanted to read books before they were illegal. Now everyone wanted them. And Xyla and I delivered— at a price.

"You make sure that new Kaptain doesn't find any of those books," she said, and then ducked back into the pipe, seeming to decide against a lecture that wouldn't work. "One of the engineers in the Tuv Trial two weeks ago was caught with a whole stack of books."

I rolled my eyes. "He wasn't thrown in for having books. He was thrown in for stealing supplies. They found the books afterwards." It was the worst offenses—stealing, fighting the K-guards, speaking against the Admiral or The Letter Trials—that got you thrown into the Tuv Pit. Usually.

"Doesn't matter," Yaneli called back. "No good comes from making enemies of the K-guards. And this Kaptain seems to particularly hate you." Nah, he called me pretty as a picture this morning, so I'd say we're getting on swell.

The radio attached to my harness crackled. I let myself slowly spin in midair, imaginary bat wings tucked in, as I lifted the radio to my chin. No voice came, so after another ten seconds of silence, I sent out my own message. "Z here. What's hanging? 'Sides us."

I grinned, expecting a joke back. Instead a sudden noise cracked over the Belly: sharp and metal and reverberating.

I righted myself, humor gone, as Yaneli reemerged. We exchanged a look that told me she was thinking the same thing as me. A gun had just fired somewhere in the Belly.

"You heard that too, right?" I whispered..

Yaneli nodded, her lips pursed. Someone had tried to radio me right before— what if it was Xyla? The guards rarely ever drew the guns at their hip; firing a gun was too dangerous with the risk of ricochet. Which meant the few times they did fire, it was to kill.

Yaneli climbed out of the pipe, staring out over the swirling smog of the Beast, something hard in her eyes. "Go back to our room, Z. Stay there till I come get you."

"Oh come on—."

"Not a discussion. Right now."

Instead of arguing, which I knew would be pointless, I released the tension in the harness and plummeted to the railing far below. My heart rose in my chest as I fell, then my metal arm seized the rope at the last moment— slowing myself in a way that would have burned the flesh of my other arm, but only heated my metal hand. I hit the metal railing hard, landing in a crouch.

Even with the pounding machines all around, the Belly seemed quieter than normal, as if the gunshot had torn a hole through the fabric of life. The smog above me slowly reformed the hole I'd made when I'd fallen, hiding Yaneli's small form far above.

And hiding me below.

For a half-second I hesitated— I really did try to listen to Yaneli, mostly, generally, okay, sometimes—but someone had tried to radio me just before the gunshot. What if it was Xyla? She could be hurt. She could need me. Surely Yaneli would understand that. And even if it wasn't her, if someone had been shot, then wasn't it my duty as a Belly doctor in training to help? Almost without a conscious decision, my feet drew me deeper into the Incinerator district, first a few tentative steps and then a full out run.

Thoughts of Yaneli disappeared as I ran through a vortex of pipes that twisted and folded, as intricate as entrails. Some carried freezing water, others were hot enough they'd melt the flesh off your hand. Most engineers passed over them, but I wove through them without slowing, unafraid. When I'd rebuilt my arm and fused the metal to the nerves of my shoulder, I built it from pieces of the Belly. I was the Belly. And the Belly protected its own.

The K-guards metal-lined boots gave them away long before I reached the scene—their vibrations sang to my metal hand every time I pressed my hands against the walkway. As I drew closer I left the metal walkways and moved up, crawling like one of the belly rats between machines and through tiny gaps, part of the shadows. Finally, I crested the back of one of the machines, the dim glow of the Belly lighting a strange scene below.