"Because you channel its magic?" I asked.

"And because I'm a flier, and one strongly tied to light. It makes the magical power of the earth and of darkness much more difficult to handle." Cass half-spread his wings, moving with an instinctual sense for where the sun was, the sunlight glaring off the metal feathers. "Come on," he said, resettling his wings. "Let's pray."

Cold air drifted out of the mouth of the cave. My arms prickled as goosebumps lifted, and I shivered, even though the cold didn't bother me. Even simply crossing the threshold of the cave gave me a sense of walking into a holy place, as if the spirits dwelled here. Beside me, Cass' wings chimed quietly, his own shiver announced by his feathers.

My eyes adjusted slowly to the dim lighting. Formless shapes resolved into pillars and stalagmites, and into the figures of hooded acolytes kneeling in the shadows. The whole floor was smooth, almost polished, a silty clay dirt showing no footprints. A series of black dots marked one stalactite; deeper in the cave, almost invisible in the dark, a strange symbol drawn in red marked the throat of a tunnel. It looked like a marker of some kind, or maybe a warning.

I knelt in front of the altar. All of the spookiness of Faery was somehow more real here. This was a land of gods and monsters. The Court thrummed beneath me, as much a living thing as the creatures that walked across it. I got the sense that if I walked into this cave – that if I let the darkness swallow me whole – the shadows would follow me out.

Cass stood behind me, a creature of the sky, and started singing in a language I didn't recognize. His sonorous voice filled the cave. I closed my eyes and let it fill me, too, until I could feel the rhythm of it like his heartbeat.

Instinct made me add my voice to his. I didn't know the song or the language, but I could tell how it would move. I sang a love-poem in Vietnamese with him, one I'd memorized years ago for a contest, full of yearning. It matched the longing in his voice, and I hit the last syllable with him, our voices melding into one.

It felt like the cave was shining, as if our voices had put sunlight in the walls. All of Mercy turned towards us, listening.

With warmth on my face and peace in my heart, I added my incense to the brazier. The scent of it filled the cave. Carefully, I plucked several of my hairs and rolled them together, then set them on the embers. "For those lost without anyone to remember," I murmured to the power of the earth. "For the people who fell to Mercy, and for those sleeping in the stone. We remember you. Mercy remembers you. Be at peace."

Cass got to one knee behind me, the heat of his body warming my back, and dropped three strands of his own hair into the brazier. They curled and burned, the acrid smoke stinging my eyes. "For all those I've slain, whether on the field of battle or in their homes and fields, I ask for mercy," he said softly, speaking in Vietnamese. "Let their memories survive when their bodies did not. Let their spirits be at peace. Let me always remember them."

My eyes went wide with surprise. But then, I'd always known my language was his, hadn't I? I'd spoken to Mercy in Vietnamese – had spoken to him – and he'd listened.

"Let's go," he whispered, still using my language. "If Ithronel answers, I think I'd prefer to be elsewhere."

I fought back a smile as he got back to his feet, then rose and followed him out of the dark. Even though we'd only been in the cave for a few minutes, it felt like emerging out of an eon of slumber, as if time ran differently underground—as if stepping over that threshold had been much more than symbolic.

Cass gave himself a hard shake, his wings rattling.

"Ready for civilization again?" I asked wryly.

"Very." The attendant started to lead our horse back over, but Cass held up his hand. "Have her sent back up to the Clement Palace," he said. "We'll fly." He got down on one knee again, proffering his arms.

I didn't hesitate. I put my arm around his neck, and let him sweep me into the sky.

Once he wasn't power-flying for altitude, I gave his braid a playful tug. "My language isn't extra magical or spiritual, you know," I said in Faery. "It's a normal language."

"I know," he replied in Vietnamese, flashing me a bright smile. "I didn't want anyone but you to understand me, though. It seemed convenient."

I took a moment to code-switch, then asked in English, "Do you know this one, too?"

He rumbled a laugh. "I do," he said in the same language. "Were you raised bilingual? Soulmate bonds come with the language of the heart. I haven't heard of anyone transferring two languages, but, then, I haven't made a study, and mortal soulmates aren't that common." He paused, frowning, then added, "At least, they usually aren't."

"I was, yeah. Do you mean Vad and Dani?" I asked.

"Among others," Cass said, switching back to his native tongue. "In the past century, there have been five fae-mortal soulmate pairings that I know of, and most of those have been in the past five years. All of them in Raven Court or its bordering Courts." His ears pinned back. "All royal fae, too. Ayre Xirangyl, who was a prince of Raven Court, and his cousin Varistan, who's the son of a princess; the crown prince of Stag Court, now King; Vaddy, who was a prince… and now me."

I blinked at the recitation. "That's weird."

"Very," he said, halfway to a growl. "I don't like it. I'm deeply grateful for you, but I dislike the pattern I've been written into." His pointed ear flicked like he was scaring off a fly. "It could simply be the approaching cometary alignment fucking with the normal order of things, but I don't think so. Sarcaryn's been involved with at least three of them, which is too much for me to easily believe it's a coincidence."

"Sarcaryn?" I asked, looking down at the encampment of cultists as we soared overhead. The sound of fervent cries drifted up.

"The stag-god of sex and beauty. He's associated with autumn color, the hunt, and desire and lust of all kinds." Cass circled over the palace, taking us down towards the wall.

The situation near the gate hadn't gotten much better with our absence. The guards had been forced to switch from keeping people off the road to keeping them from trying to rush after us, penning the cultists up against the cliffside. Angry chanting floated up, sounding like something from videos of protests, but the words were garbled enough from the distance that I couldn't make them out. People were inches away from guards, shouting, and I caught sight of little knots of people being tended, blood on their faces and hands.

Guards three men deep blockaded the far end of the drawbridge, trying to keep people off of it, but Cass' shadow had alerted people to his presence. Desperate people pointed at the sky and cried out. More shoved their way towards the drawbridge, trying to get to the palace walls.

Cass' arms tensed on me. The wind picked up, lashing at my hair and tearing leaves off of trees. He growled and cocked his wings, throwing us into a shallow dive, heading for one of the rooftop doors.