None of them were real.

Aisling readjusted her grip on the anchor post behind her and began the steady process of pulling herself back in. She did so painstakingly to avoid jarring the post, but this one wasn’t as steady as the others had been. As Aisling tugged, it lurched sharply to one side as the base began to lose its purchase in the rock. Her lungs seized as she went with it, her body pitching out over the canyon.

She swung her free arm wildly to regain some balance, to find some momentum that would let her right herself before the post collapsed entirely. Only one of her feet was still on the cliff. Aisling dug it in, twisting and contorting until she could reach around and seize the post with both hands. It leaned and leanedas she struggled against gravity until finally, half-blind with panic, she managed to maneuver herself back onto the ledge.

Aisling collapsed onto the rock, chest heaving. She dug her fingers in and pressed herself against the ground as firmly as she could. She wanted it to be touching every inch of her.

“Holy shit,” she breathed. A sick, hysterical sort of giggle bubbled up her throat before she could stop it, and then she was laying there laughing—at herself, at this nightmare of a challenge. At the thought that she might have been able to outsmart a god.

It took her several minutes to come back down from that adrenaline-induced delirium. Still panting, Aisling propped up on her elbows and looked out across the canyon. And it took another minute still for her to regain enough clarity to realize something important.

Between Seb’s bridge and Lida’s in the center, where her hand had grasped at empty air, she hadn’t felt any wind. Not a breeze, not a rustle. Nothing at all.

Aisling didn’t allow herself the time to think it through. She knew if she took a minute, thirty seconds, ten, even, she’d talk herself out of it. So she stood and moved forward, towards the space between the two bridges. Closed her eyes. Then stepped off the ledge.

Onto solid, invisible ground.

A hidden bridge.

Walls of wind threatened her balance on either side, but if she stayed centered—absolutely, dead centered—she could only barely feel the air brushing past her outstretched fingertips. Just as she had as she’d paced the ledge, Aisling lined up her heels with her toes to make sure she kept moving in a straight line. Beneath her feet the canyon yawned, wide and vacuous. Like it wanted her, like it was waiting to swallow her up. Her stomach flipped each time she shifted her weight forward, certain thatthe next step would be the one that sent her plummeting. Or the next. Or the next.

Until—land. Solid ground. Aisling could have wept from sheer relief, could have dropped straight onto her knees and kissed the stone. But as she took the final step off of that invisible bridge, the world around her wavered and faded and dissolved into black.

Yalde wasn’t waiting there in her mind this time. There were no whispers, no derision for failing once more to use the answer to his riddle to escape the arena. This time, there was only silence.

Before she opened her eyes, even before the darkness had cleared, Aisling knew where she was. She knew it by smell: damp earth, burning torches, spent magic, groundwater eroding ancient stone.

The Undercastle.

She was in the center of the cavernous throne room, just as resplendent now as it was the last time she’d stood there, asking the Silver Saints to close the Veil. Except without their pale white glow, it was far more somber. It was different, too, in a way Aisling had trouble identifying at first. It wasn’t until she took a step in the direction of the throne that she realized what set this incarnation of the Undercastle apart: everything was flipped, a mirror image of itself. The banquet table that should have been on her left was now on her right. The door that Kael had led herthrough behind the dais on Nocturne was on the opposite side of his empty obsidian throne.

It was slightly dizzying to see it this way. It took Aisling a moment to get her bearings, her brain struggling to make sense of this echo of the place she’d come to know. She approached the dais slowly, cautiously. Her footsteps sounded like thunder in the hallowed stillness of that dark place.

She wasn’t sure how her shadow might lead her out of there, but for a short while, not more than a minute or two, she let that concern go. Aisling ran tentative fingers over the arm of the throne, then its back. The sharp edges and smooth stone were cool to the touch, but she imagined it warm. Imagined that Kael had been sitting in it only just before she’d arrived, and that it still held some of his body heat.

She let her gaze wander over the chiseled patterns until it settled on another set of carvings. Circling the throne, Aisling descended the dais and approached the far wall. Markings were etched into the stone beside the doorway; delicate, looping symbols that were so foreign, and yet so familiar.

Leaning in, Aisling squinted to make out the words in the barely-there light. She smoothed the pad of one finger over the closest set, and her heart clenched when she realized just what she was looking at. Each letter, each sloping line and intricate curl—she couldn’t read the Fae language, but she recognized it.Kael’s handwriting. Aisling pressed her palm over the nearest word, then twisted to take in the rest of the space.

The writing was everywhere: carved into the floor, into the walls, swirling across every surface up and up until the letters disappeared into the darkness with the cavern’s soaring ceiling. It was Kael, all of it; he was all around her. She examined the text again as though she might suddenly be able to read it. As though the words would bring her closer to Kael. As though they were a message left purposefully: a letter written on the walls to guideher, or encourage her, or confess everything she hoped he still felt somewhere in his heart for her.

Aisling closed her eyes then and leaned forward until her forehead rested against the wall. She could feel the indentations of the script there on her skin.

“Help me.” She whispered the plea like he could hear her through the words.

She opened her eyes and studied the writing a moment more. The letters looked so like those she’d seen embossed in gold on the spines of the books in Kael’s study, but not quite identical. Slanted in the wrong direction, loops curving to the left instead of the right.

Backwards. The letters were written backwards.

Aisling pulled away from the wall and turned around again, spinning in a slow circle. The Undercastle was flipped; Kael’s writing was backwards. Every arena she’d encountered before had been so uncanny, just far enough from normal that it raised the hair on the back of her neck and brought an uncomfortable tension to settle in the pit of her stomach.

Wrapping her arms around her waist to fight off the stubborn chill, Aisling fled the cavern and aimed for the hall. It was a longshot, she knew it was, but in the most desperate corner of her mind it made sense:find the spiral stairs, find the way out. She kept one shoulder against the wall as she walked, using it as a guide to negotiate the darkened, backwards corridors. The Undercastle was difficult enough to navigate under the best conditions; the challenge of finding her way through a mirrored version had Aisling even more on edge than she’d felt standing on that invisible bridge above the canyon. She’d never once in her life been lost before, not truly. Not like she could get lost down here.

The atmosphere changed as she walked, growing more and more oppressive with each step. The walls were closing in; shecould feel the weight of rock and earth settling around her. She could see the base of the stone steps ahead at the end of the corridor, but she couldn’t taste the fresh air that the entrance let in. Aisling ran to it, skidding to a stop in the center of the spiral and squinting up into the dark. The tunnel of rock around the stairs became increasingly narrower, darker. Just at the point where her eyes could barely distinguish between surfaces, the rock turned to black, hard-packed dirt.

The vertigo that came with the view forced Aisling to sit heavily on the bottom step. She was looking up, looking straight up, but the stairs were burrowing down, deeper and deeper into the earth. Her mind and her body couldn’t quite reconcile the reality of what she was seeing with the expectation, the certainty of up being up. That up was now down made her pulse race and filled her mouth with cotton. She folded forward and put her head between her knees.

Gradually, the Undercastle gradually stopped spinning around her. The floor stilled beneath her feet enough that she could stand again without the threat of passing out. Without looking back up—down—at the spiral stairs again, Aisling made her way back to the throne room.