The sewer tunnel reeked of rot and raw time. Black water sloshed to their knees as Reg and Isabella ran, the fused gear burning between their clasped hands like a second heart. Brass veins pulsed in the walls, leaking centuries in slow black drips that hissed where they touched skin. Every drop aged the bricks a decade in seconds.
"Keep moving!" Reg gasped. "The Bishop's enforcers are seconds behind literally."
Isabella's shadow still lagged, but the fused gear synced them now. When she stumbled, he felt it in his own blood and steadied her without looking. Their heartbeats hammered as one. "This thing is knitting us together," she panted. "I can feel your opium tremor. You feel my family's guilt. It's too much."
A vein burst ahead, thick as a ship's cable, whipping across the tunnel. It screamed with the voices of unborn children. Reg slowed time with a savage push stolen seconds flaring hot and yanked Isabella under the lash. The vein struck the opposite wall instead, crumbling stone into dust.
They splashed onward. Behind them, silver syringes whistled through the dark. Enforcers had entered the sewer. Lanterns swung, masks gleaming. The Bishop's velvet voice echoed, calm and terrible. "Daughter of the Anchor, come home. Your blood calls. The Clock-God forgives the thief if he surrenders you."
Isabella snarled. "I am not your daughter!"
Reg pulled her into a side tunnel, narrower, darker. "We have to test this alliance right now. The gear only works when we push together. One heartbeat each. Trust me on three."
She met his eyes steel meeting storm. "One."
A vein erupted between them, spraying black blood that burned like acid.
"Two."
The blood hit Isabella's cloak, eating through velvet to skin. She cried out, but didn't flinch.
"Three—now!"
They slammed their joined hands onto the gear. Time fractured. The vein aged backward, ribs rusting, blood drying to powder. The enforcers' lanterns froze mid-swing. Reg and Isabella ran through the stalled moment, breaths synced, legs pounding in perfect rhythm.
They burst into a wider chamber—an old smugglers' vault, half-flooded, walls carved with forgotten clock faces. The gear cooled slightly, but their pulses still thrummed as one. Isabella leaned against him, breathing hard. "It worked. We stopped it. Together."
Reg nodded, but his face was grim. "For now. The fusion… it's costing us. Every joint push burns one of our shared seconds permanently. We just lost forty-three. I felt them die."
Isabella's hand tightened on his. "Then we use them wisely. Tell me the truth you've been hiding, Clockmaker. Why did you really steal that gear three years ago?"
He looked away. "Eleanor. My wife. The surgeons bled her final thirty-seven seconds for my patent. I thought if I could reverse the flow—steal time instead of paying—I could bring some of her back. One honest day. Stupid. Selfish."
She touched his cheek, two seconds late but real. "Not stupid. Human."
A soft tick-tock echoed from above. Little Thread sat on a ledge, legs dangling, broken watch open. Inside, the Bishop's stolen second pulsed beside Isabella's shadow and a new golden thread—Reg's own.
"You're learning fast," the child whispered. "But the Clock-God doesn't share anchors. One must break for the other to survive. Choose now, thief. Push every fused second into her bloodline and snap the original chain. She dies, but the century lives. Or keep her, and the veins split wider. Every future child unravels. Starting with the ones she would have borne."
Isabella went still. "He's lying."
Little Thread smiled. "Am I? Feel it."
The gear flared. Visions crashed in: a thousand futures where Isabella lived—happy, free, mother to sons who would never age. Then those sons screaming as their timelines shredded. London crumbling into static. The Unseen Clock laughing.
Reg's stomach twisted. The choice was real. Save the woman whose heartbeat now beat with his, or save everything that came after.
Isabella's voice cracked. "Don't you dare choose me."
The tunnel walls shuddered. A massive vein thicker than a carriage rose behind Little Thread, reaching for them both. Enforcers' boots splashed closer. The Bishop's laugh rolled like reversed thunder.
Reg gripped the gear, heart hammering against Isabella's in perfect, terrible sync.
The choice burned in his blood.