Light and chord swallowed them whole.
Aric felt himself pulled through a tube of glass and sound, every heartbeat stretched into a drumbeat. The Mirror's pulse aligned with the living fragment's chime until the two rhythms became one. Lyra's grip on his sleeve was the only thing anchoring him.
Then, with a lurch, they fell out of the tunnel and hit solid ground.
The world slammed back into place: heat, steam, a clang of metal. They were standing on a catwalk suspended over a cavern filled with machinery. Above, a black ceiling vanished into mist. Below, a labyrinth of colossal gears turned in slow, grinding cycles, each tooth taller than a man. Red light glowed from cracks in the machinery, painting everything the colour of smouldering coals.
Lyra coughed, waving a hand in front of her face. "Next time, Vale, warn me before we step through an interdimensional furnace."
"I told you it would be somewhere new," he said, setting the cage down. "Didn't say it would be comfortable."
Her eyes narrowed. "Comfortable is not the word I'd use. 'About to die in a giant engine' is closer."
"Too many words," he murmured. "And I count at least three ways off this catwalk, so not dead yet."
The three mask-bearers arrived behind them in a staggered line, their black coats snapping in the hot drafts. Even through their ceramic masks, Aric could sense their unease. This wasn't a place any of them recognised.
One of them muttered, voice distorted by the filter. "Where are we?"
Aric pointed down. "Inside a myth, apparently."
The leader ignored him and scanned the cavern. "This is an active engine."
Lyra arched a brow. "Active? It looks like it's dying."
She wasn't wrong. The huge gears shuddered with each rotation, spewing bursts of red sparks. Steam vented from ruptured pipes in intermittent sighs. The air smelled of scorched copper and salt. A high, metallic whine trembled through the catwalk like an insect's wings.
Aric crouched by the cage. The fragment inside pulsed faster, filaments stretching toward the heat below as if drawn. The Mirror hummed in answer.
He whispered, "It wanted us here."
Lyra crouched beside him. "For what?"
Before he could answer, a deep clang echoed from somewhere below. The gears stuttered, then locked. Silence fell, heavy and wrong.
Then something moved in the red light.
At first it looked like another gear disengaging. Then it rose, towering over the machinery: a segmented shape of iron and bone, each joint hissing steam. Eyes—if they were eyes—glowed like molten coals along its body. A grinding voice filled the cavern, not words but a vibration that made their teeth ache.
Lyra swallowed. "Please tell me that's not alive."
Aric's jaw clenched. "That's alive."
One of the mask-bearers hissed, "The Red Engine."
"You know it?" Aric asked.
"A Depthborn remnant. It eats echo fragments to keep its furnace lit. And it's looking at us."
As if on cue, the Red Engine's head pivoted. Steam hissed from vents along its neck. The gears beneath it began to spin backward, pulling the catwalk slowly toward the creature.
Lyra muttered, "Well, Vale. You wanted new experiences."
Aric's lips quirked. "I was hoping for a coffee shop."
"Next time, we're going to a coffee shop," she snapped, drawing threads of light between her fingers.
The mask-bearers spread out, staffs raised. "Hold the fragment!" the leader barked.
"No," Aric said. "We need it." He slung the cage over his back, feeling its frantic chime against his spine. "You three slow it down. Lyra, with me."
She shot him a sideways look. "Do you have a plan?"
"Workshopping one."
"Fantastic. I always dreamed of dying in a beta-test."
He smirked despite himself and moved.
The catwalk trembled as the Red Engine advanced, each step a hammer on the gears below. Steam hissed from ruptured pipes, turning the air into a scalding fog. Aric's eyes darted to the walls—arrays of broken valves, inactive consoles, and, high above, a cluster of glowing runes etched into a control panel.
"There," he muttered.
Lyra followed his gaze. "You're thinking of shutting it off?"
"I'm thinking of making it choke."
They sprinted along the catwalk, the fragment's chime growing frantic. Behind them the mask-bearers unleashed prism bolts—sharp bursts of violet light that struck the Red Engine's armor, leaving glowing scars but no real damage. The creature roared, a blast of steam sweeping across the catwalk and knocking one bearer to his knees.
Lyra sent threads lashing out, hooking a dangling chain and swinging herself to a lower platform. "Come on, Vale!"
He followed, landing hard on the metal grating. Heat rose through his boots, searing his soles. Ahead, the control panel flickered weakly. He reached it, brushing ash off the runes. The Mirror pulsed, overlaying chords across the symbols—translations, functions, pathways.
"I can reroute the flow," he said. "If I open these gates, the Engine starves for a second."
Lyra glanced back. The Red Engine had reached the catwalk, crushing metal under its weight. Steam and sparks rained like a storm.
"How long is 'a second'?"
"Long enough to move."
She grimaced. "Do it."
Aric pressed the Mirror to the runes. The panel hissed, lights flaring. Deep below, gears shifted, and for a heartbeat the Red Engine faltered, its glow dimming.
"Now!" he shouted.
Lyra flung her threads outward, creating a shimmering rope across the gap to another platform. "Move, Vale!"
He grabbed the rope and swung, the cage clanging against his back. They landed hard, rolling to their feet. Behind them the Engine roared, its furnace flaring bright again as it tore through the catwalk in a spray of molten metal.
One of the mask-bearers screamed—a short, cut-off sound. Aric glanced back just in time to see a prism staff vanish into the Engine's furnace, light snuffed out.
"Two left," Lyra panted.
"And they're buying us time." Aric's chest heaved. The Mirror burned cold in his hand, showing lines of possible paths—spirals leading upward, downward, inward.
He picked one and ran.
They scrambled up a staircase carved into the cavern wall, steam hissing from vents on either side. The Red Engine followed, its massive body twisting to climb after them. Sparks rained down, setting Lyra's hair alight for an instant before she smothered it with a curse.
"I am never trusting you again," she snapped.
"Noted," he said.
They reached a narrow ledge overlooking the furnace pit. Above them hung another chain, this one connected to a massive valve wheel set into the wall.
Aric looked at it, then at Lyra. "If we drop that wheel, the valve opens. Engine gets a faceful of backflow."
She stared at the distance. "That's at least a three-metre jump."
"Good thing you're athletic."
"Good thing you're carrying the cage."
He blinked. "Wait, what—"
She shoved the cage into his arms. "Hold this." Then she sprinted, threads lashing out to hook the wheel. She swung across the pit, boots skimming the heat rising from below, and slammed into the valve. Metal shrieked.
"Now turn it!" Aric shouted.
"I'm trying!" she yelled back, straining. The wheel groaned, then spun. A hiss of high-pressure steam burst from the pipes above, cascading down onto the Red Engine like boiling rain.
The creature roared, its glow flickering. For a moment it reared back, thrashing. Gears jammed below, the entire cavern shuddering.
Aric saw his chance. He grabbed the dangling chain Lyra had used and swung across to her side, the cage pressed tight to his chest.
She gasped, clinging to the valve. "You're insane."
"Occupational hazard," he said. "Come on!"
They scrambled through a maintenance hatch as the Engine's furnace flared back to life. Behind them the mask-bearers' shouts were lost in the roar of steam. The hatch slammed shut, cutting off the heat and noise. They collapsed in a narrow tunnel lit by faint blue veins.
For a moment neither spoke, only the fragment's soft chime filling the silence.
Then Lyra groaned. "Next time we're picking the coffee shop."
Aric managed a weak laugh. "Deal."
The fragment pulsed again, brighter now. Aric frowned. "It's changing."
Lyra sat up. "Changing how?"
He held the cage up. The pale filaments inside had shifted, coalescing into something vaguely humanoid—small, like a child crouched in the bars. Two luminous eyes opened, fixing on him. A thin voice, high and cracked, whispered from the cage:
"Path… chosen…"
Aric's breath caught. "It can talk."
Lyra stared. "That's… impossible."
The fragment's eyes burned brighter. "The next gate opens… in blood…"
The Mirror in Aric's satchel vibrated violently, symbols racing across his vision. A new chord etched itself into his mind—red and jagged, like a wound.
The tunnel shuddered. Somewhere far behind them, the Red Engine roared again.
Lyra's hand found his arm. "Vale—what did it just say?"
He looked at her, the cage trembling in his grip. "It said the next gate opens in blood."