The trip up the bookshelves went uneventfully, but the apexes were proving otherwise. Ruvle leapt, one bookshelf top to another. A hard grunt of effort announced her landing, after over a six-meter distance. She panted. “And that’s my stupid stunt.”

  “Doesn’t count, you can go stupider,” Chain answered, matter-of-factly, and climbed out of her arms. “Seriously though, sick leap.” He cackled.

  “Why is the air thinner here than…” She took a few more sharp breaths while Chain looked around, his eyes apparently keener in finding something. Ruvle couldn’t be sure if...if that haze thickened since they entered twenty minutes ago? It hadn’t encroached closer, and yet, it felt harder to turn sensory information into comprehended objects now. Everything close-up still had something vaguely like color, but it had to be close. “...than on the mountain we were just on?” The foothills, but…

  “Good question!” He looked over his shoulder at her, and winked. “Next question!”

  She stepped on over to him, aware of a vague blob of tislet blue at the edge of her haze radius. Getting closer, she could see the details–they’d reached an interior wall of the alcazar, the same drywall he’d used for his workstation, and it had much more to reveal than books. At this bookshelf-top level, a slotted metal grate formed a portcullis, as if one were intended to walk from the shelf’s top into the narrow hallway beyond it. Compared to the monoliths of education below, what lay in that hall seemed quaint–a simple writing desk, chair, closed inkwell, and a single cloth-bound book sitting on the desk–long-abandoned, it seemed. Before the hollow, the glowing blobs of blue came into clarity–looped bundles of tightly-compressed tislets suspended in the air with disorder, the size of her torso, with ray-like extensions of additional tislets orbiting outwards. They reminded her of ribbons on extravagantly large bows, or those drawings of electrons around an atomic nucleus. Ruvle should bring a bow next time. She could put it in her hair and it would glow bright blue. If Chain brought her here again, it would make her look pretty. People were more affectionate when you looked pretty. …Focus. She brought herself back to the place at-hand. “...Are these the clusters you mentioned?”

  “Yeah! Five of these here…uh…” He started pointing around, scratching his hair with his other hand. “Okay. That one will make a zone if you touch it. I don’t know what that zone will do, so let’s not. That one, I have no idea. That one makes…a specific…it makes something stretchy, I think, and I can’t tell what because I don’t know who wrote these, but context clues say it’s probably paper. That other one is completely incomprehensible, I’m not even gonna try. And…” he narrowed his eyes. “I can solve this one,” he said, and approached, scrunching his shoulders and ducking his head to get underneath them–the bookshelf, though large, behaved as a narrow hallway when walking along its top. “Gotta scoot past…”

  “I don’t know if you can get under those without touching one…” Ruvle said. She could, obviously.

  “It’s fine, you just don’t touch the centers.”

  Oh, then he had plenty of space; they had obvious square gridlock arrangements of tislets at their centers. “Are these here to protect that grate?” she asked. “If they are, then…why are they…avoidable?”

  “These are everywhere,” Chain said, sneaking around the one that would make a ‘zone’. Ruvle narrowed her eye at it, tilting her head just right, so as to look at the core of tislets side-on–and they disappeared to her view. It felt strange to think of two-dimensional symbols, with no thickness, as having a volume, but there was some internal order about it. They spaced off of one another at a fixed, narrow distance, the same distance that they hovered above the fabric of Chain’s scarf. Wide enough that she could slip a lock of hair between his scarf and its scrivenings, but not her little finger. “All of the out-of-the-way places have a bunch,” he continued, “but I think that’s because all the in-the-way ones got pushed to corners. …I’m gonna need a few minutes for this.”

  She gave him his time. She did simple stretches while he waited–casual splits, backbends, bending over to put her palms on the floor, the basics that Gross-level gymnasts could do.

  “This puzzle’s hard,” he said, chuckling, while he erased and scrivened with his finger, replacing strings of tislets in the gridded center.

  “That can’t be a puzzle,” Ruvle said.

  “It’s not, but I like to think of these that way. Clusters usually have a way they can fall apart without activating them. So when I learn new tislets, I try to use them to defuse a cluster, so I get some practice figuring them out. …nice, look at that, all these strokes lining up, cutting the whole square in half…isn’t that pretty?” he asked.

  Ruvle just smiled.

  Chain eventually judged that he’d made something sufficiently beautiful by rearranging the loose parts, and then with one final stroke of his finger, the tislets disassembled and fell, scattering like spilled ball bearings. Most of them vanished shortly; others stuck to books or to spots on the wood of the bookshelf, isolated into pairs–they’d fallen with their backs to one another, as if using their partners as surfaces. Ruvle did not know how to tell if they’d do something in this state, given the 10% extension comet parable Chain had applied to get her inside, or if they had become harmless by being separated, given what Chain once said about lacking meaning on their own. He seemed unbothered as he continued sneaking past. Maybe the latter. Maybe he intentionally chose not to worry.

  Stolen content warning: this tale belongs on Royal Road. Report any occurrences elsewhere.

  She walked through the other clusters with Elial’s ease and met him at the grate. His fingers plucked at the bars, too closely-spaced to fit the base of his thumb through. “Singletons,” he said. “That’s what these little extra rooms on walls and ceilings are called. Sometimes small, sometimes giant multi connected areas.”

  “They look cozy,” Ruvle said.

  “Nah, they’re crazy dangerous,” he said. “You know how dynamite used to leak the nitroglycerin out and make crystals of it on the outside, so it looked like a normal dynamite stick if you weren’t paying attention but it’d blow up if you touched it wrong?”

  “Yeah.” Modern dynamite at a fireworks shop was much safer.

  Chain looked around at the walls inside the singleton room. “That, but with tislets.”

  Ruvle focused hard, and could sort of see patches of filtered blue glow, behind wallpaper and glittering off the inkwell. Hidden inside, overlapping…she struggled to come up with the spatial relation. “I hope there’s nothing in there you need.”

  “Nope. The book looks kinda nice; we recycle that cloth to make scarves for new scriveners,” he said. “But let’s not.”

  “I won’t risk my life for cloth,” Ruvle agreed. Not unless it was bound in solid Dye. “Where else should we go?”

  “Underneath,” he said, unhesitating. “I’ll find a good spot. Follow me.”

  Ruvle returned with him to the other edge of the bookshelf. Chain judged the impenetrable sphere of haze around him, shrugged, then jumped off to parachute down. With her reflexes so much faster now, she didn’t need warning–she simply hopped onto the top of the parachute before it disappeared behind the haze horizon, and let him guide her through nothing.

  Thinking back to the cloth-bound book, Ruvle reflected that just because she had the willpower to make a sacrifice–the lack of morals, in some cases–it didn’t obligate her to do so. Some sacrifices were unsound.

  Unnecessary. Maybe that was the better word. And she pouted to herself, wondering–if that couldn’t be her edge against the world, what could?

  After landing, and much more walking around, Ruvle felt aimless. Not just mentally, but physically–the tiled floor stretched out into a horizon she couldn’t see. The guiding lines of the tiles prevented Chain from walking in circles, but that only cemented to Ruvle the vacuousness of the alcazar, away from the bookshelves and wall decorations–like an ant traversing the wide open spaces in the middle of the library. A bacterium, even.

  Chain talked her through it. Away from shelves and walls, they could walk for days in a straight line and see nothing. The ceiling sloped, according to him, though she couldn’t see it–going up and up in these no-man’s-lands, only reasonably reachable at the edges. He was making a point of moving laterally rather than advancing into the no-man’s-land, and Ruvle confirmed that with her mental mapping. She wondered if the haze continued to play tricks on her, feeling phantom moisture on her skin–only for it to become a gentle but inarguable drizzle, which smelled unhealthy. That was the fate of evaporation from the pages of the books, the wood, and more recently those who explored inside, according to Chain. It’d become vapor again, sometime, a water cycle, with the grouting between impermeable tiles being a floodplain. Some day, he imagined, today’s evaporated sweat from Ruvle’s skin would fall on a future tislet user. She didn’t know how to feel about that.

  “Will we be able to get back from here?” Ruvle asked, after another thirty minutes of walking. Nothing made sense and she wanted to be home. With Dad. With Elial, even.

  “We will,” he assured her, now stopping to crouch at another two-meter tile that caught his eye. His hand brushed along the surface. “We don’t have to go back to where we started, we just repeat the entry method and we’ll exit the same.” Chain started scrivening on the tile with his finger, following old burned-in grooves, each looking like the ghost of a tislet on its own. “This one’s a spot between the stonework…so we should be able to drop down under it…” he mumbles. “Everyone’s using a variation on the same sequence, so I can follow the general idea. Except this one part doesn’t make any sense at all and I’m doing it my way,” he added, with a chuckle.

  Ruvle didn’t return the laugh.

  He spent another ten precious minutes backtracking and making sense of what in the world he was sequencing out, having to improvise it all halfway through–everyone needed to use a different sequence for their own mind, after all, so the grooves of worn tislets eventually diverged into unreadable overlapping smudges, but Chain learned. His sequence brightened and disappeared, adding its burn to the indistinct mess. “Right! Okay, help me bend this up.”

  Ruvle did as told, again. The tile behaved like sheet metal–not easy to bend, but with two people, they pulled up one corner enough for Ruvle to slip down into the hollow below and start pushing with her legs, which opened it further for Chain to enter. He had to parachute down the vertical corridor between solid slabs of worked stone, like an unnatural elevator shaft to the foundations of the building. Ruvle slid only along a corner between two walls, jumping to another whenever traction tired of her nonsense.

  And in the dark maze of timbers, stone, mysterious concrete and sealants below, lit only by Chain’s scarf, Ruvle no longer even tried to mentally map where she went. Too hard. Too fuzzy.

  Minutes passed. She held his hand tightly, letting his steps be her guide.

  He found it, at the edge.

  “See, isn’t that something?”

  His scarf’s light no longer mattered at the edge of the alcazar. They looked out through a gap in the foundation to see millions, billions of light glows, tislets passing by in sheets and columns, as a cloud of infinite distance beyond the pale, shining impossibly through the haze–like square stars that blanketed every inch of the night sky, until it better resembled the day.