The vault doors shuddered under the weight of the world outside. Somewhere above, stone fractured with the sound of splitting bones. The keep was collapsing in pieces, every impact reverberating through the marble like drumbeats from the underworld.
Aerin pulled Jayden toward the rear exit of the vault. "We're not dying down here."
But Jayden's legs felt heavy. The second rhythm in his chest was louder now—impossible to ignore. It wasn't beating in time with his pulse anymore; it was dictating it.Boom… boom… boom.
He tried to push it down, to smother it in silver flame. The flame flared, but instead of burning the rhythm away, it twined with it, latching on.
Aerin noticed his stumble. "Jayden—"
"I'm fine," he lied, the word tasting brittle. "Go."
They burst from the vault into a long corridor lined with statues—each one a robed figure holding a mirror. Most were cracked or clouded with age, but as they ran, Jayden saw the reflections inside moving. Soldiers he didn't recognize. Cities burning. A black sky split by a silver tear.
The second rhythm inside him surged at the sight.
They're not visions, something whispered in his mind. They are doors.
Aerin's torchlight cast their shadows long behind them, but the sound following was longer—boots, claws, and something scraping the walls. Jayden risked a glance back.
A half-dozen Shadowborn surged after them, moving like they had no bones to hinder them. Their armor smoked where the moonstone light touched it, but it didn't slow them.
Aerin stopped in the middle of the hall and planted the torch between the flagstones. Its flame leapt high, becoming a curtain of pale fire that hissed where Shadowborn skin brushed it. "Buy us two breaths," she said, shoving Jayden toward a narrow spiral stair at the far end.
He took the first step—then froze.
At the top of the stair, a figure stood silhouetted against the moonlight streaming from an open balcony. Not the masked one from the vault—this was smaller, leaner, wearing armor inlaid with veins of silver that pulsed like veins under skin. In one hand they carried a blade so black it seemed to drink the light.
They didn't move. Just waited.
Jayden knew a trap when he saw one. But something in him pulled toward them, the second rhythm urging him forward, like it knew this person.
Behind him, Aerin's voice cut through the din. "Move!"
The Shadowborn at the far end of the hall began screaming. Not in pain—something else. A keening wail that made the hair on Jayden's arms rise.
The silver-armored figure tilted their head, the gesture eerily similar to the masked one's. "The Heart is waking," they said, voice calm even as the keep shook. "You shouldn't be here when it fully opens."
Jayden's grip tightened on his own sword. "And you are?"
They took a single step closer. "One of the few who remember what it cost to bind it last time."
The second rhythm inside him lurched, like a heart skipping a beat. He almost dropped the blade.
Then the ceiling above the stair gave way with a roar, stones and dust collapsing between them. The silver figure didn't flinch—just turned, stepped onto the balcony, and vaulted into the night as if gravity were optional.
Aerin appeared at his side, coughing through the dust. "Who—"
"No idea," Jayden said quickly. He didn't want to explain—not here, not now. "We need another way up."
They cut left into an unlit passage, the sound of battle thickening as they neared the central hall. The crash of steel, the roar of dragonfire, the gut-deep thud of siege impacts—it all merged into a storm of noise.
They emerged onto a gallery overlooking the keep's grand foyer. The sight below froze Jayden's breath.
Shadowborn poured through the shattered gates in a black tide. The ward-lights were gone, the golden runes along the archways reduced to jagged lines of dead stone. The defenders—human, dragonkin, and griffin riders—were already fighting in retreat, their formation folding toward the spiral stairs leading to the royal family's chambers.
And above it all, on the marble dais at the foot of the stairs, stood the masked figure from the vault. Their cloak billowed like it was caught in a wind no one else could feel. In one hand, they held a shard of something pale and crystalline, pulsing faintly—like it was in time with Jayden's own chest.
The Second Heart's rhythm spiked. His vision blurred for half a breath, the world narrowing until all he could see was them.
They looked up at the gallery. Straight at him.
Now, the second rhythm urged. Go to them.
Jayden's hand clenched so hard on his sword hilt that the leather bit into his palm.
"Jayden," Aerin said sharply. "Stay with me."
He nodded, but the truth was already gnawing at him. Staying away from the masked figure felt like trying to fight the pull of the tide with bare hands.
Somewhere in the chaos below, a great horn blew again—three deep notes. A retreat signal.
The royal guard was falling back to the last sanctuary.
The final stand.
And Jayden knew—if he followed them there, he'd be walking straight into whatever the masked figure had been waiting for.
The gallery's far door was half off its hinges, moonsteel bent like soft tin. Aerin shoved it aside, and they plunged into a dim, narrow bridge of stone suspended above the inner courtyard.
Below, the fighting was worse. The Shadowborn were no longer moving in neat formations—they were everywhere at once, climbing walls, hurling spears of frost, leaping from rooftop to rooftop. The air smelled of burning pitch and cold iron, each breath scraping the inside of Jayden's throat raw.
From somewhere deep in the keep came the heavy clang of the sanctuary gates locking into place. That sound, more than the chaos below, sank into Jayden's bones.
They were sealing themselves in.
"Come on," Aerin urged, pulling him toward the west tower. The bridge swayed slightly with each tremor from below.
Jayden forced his legs to move, but the second rhythm was hammering now, each beat echoing like it wanted to break through his ribs. Every pulse seemed to pull his gaze back—back toward the masked figure in the grand foyer, still standing on that dais.
At one point, their eyes met again across the courtyard's chaos. The figure didn't shout, didn't move—just lifted their hand and curled their fingers once.
It was the most casual gesture in the world. But Jayden felt the tug like a hook in his chest.
By the time they reached the tower stairs, his hands were shaking.
The west tower's interior was a blur of shouted orders and fleeing servants. Guards in dented armor rushed past them, some missing helms, others bleeding from wounds already frosting over. Jayden caught fragments of their words:"…hold them off at the north stair…""…sanctuary can't hold more than two hundred…""…ward-sigils gone cold…"
By the time they reached the top level, the heat from the braziers was a lie; the air was so cold, their breaths came out as mist.
Aerin led them into a massive circular chamber—the sanctuary itself. Its walls were carved with ward runes so deep they looked like rivers frozen mid-flow, each groove inlaid with moon-gold. The ceiling arched high above into a dome, from which hung a single black bell that swayed gently without sound.
Dozens of survivors were already huddled inside: the royal family's younger cousins, wounded soldiers, a cluster of mages murmuring counterspells under their breath. At the far end, a thick set of double doors—reinforced with bands of silver and iron—stood shut.
And in the center, on a raised platform, an ancient pedestal waited. It was empty.
Jayden stopped short. "Where's the Heart's vessel?"
Aerin's voice was tight. "Moved. Months ago. The vault was a decoy."
Jayden stared at her. "You could've told me—"
Her gaze flicked toward the survivors. "And let everyone know where the real one was hidden? You think spies don't hear?"
He wanted to argue, but the second rhythm inside him surged again—this time accompanied by a faint sound. Like a low hum under the ward-gold's glow.
The mages' voices faltered.
Jayden looked up.
A crack was forming in the ward-carved walls.
It didn't start big—just a hairline fracture in one golden rune near the doors. But instead of stopping at the stone, the crack spread into the air itself, spiderwebbing across the surface of the sanctuary's magic.
Aerin swore. "How—"
The answer came in the form of a voice. Not loud, but deep enough to be heard over every other sound.
"Jayden."
Everyone in the room froze. The syllables didn't come from the door or the walls—they came from inside their heads.
"The wards will not keep me out."
The second rhythm inside him answered like it had been waiting for the call. For the first time, the silver flame in him didn't feel separate from the shadow—it was blending, knotting together until he couldn't tell where one ended and the other began.
Aerin grabbed his shoulder hard enough to bruise. "Ignore it."
"I—" His throat locked. He couldn't finish.
The air in front of the doors went black. Not absence-of-light black—this was heavier, a darkness that seemed to sag the floor beneath it. From it stepped the masked figure, as if they'd simply chosen to bypass the silver-and-iron entirely.
Gasps rippled through the survivors. Half a dozen guards raised spears.
The figure didn't even glance at them. Their gaze locked on Jayden.
"You know what I am," they said, voice carrying perfectly through the chamber.
Jayden's heartbeat thundered in his ears. "I think I do."
They stepped forward, each movement silent despite the weight of their cloak. "And you know this place cannot hold against me."
The mages cast in unison—rings of moonlight flaring from their hands. The figure walked straight through. The light dimmed to ash.
Gasps turned to shouts.
Aerin moved in front of Jayden, torch in hand, but the figure simply extended a palm toward her. The frost shot from their fingertips in a perfect spiral—and froze the flame mid-burn.
Jayden's hand went to his sword, but the masked figure didn't draw a weapon. They only stopped a few feet away and tilted their head.
"The choice," they said softly, "is whether you come now… or after they've all died."
Behind them, the crack in the ward-gold spread faster.
Jayden realized, with a sick lurch, that the figure didn't even need to fight their way in. The Second Heart inside him was already doing the work for them.