“That’s a nice side effect, but the real benefit’s for the surgeon. Patients thrash when you cut them open. The body fights intrusion. Muscles clench and skew the scalpel.” Another peristaltic tremor passed underfoot. False sunset lit the curving tunnel wall ahead. She smelled ozone and salt and bone. Something creaked. She hoped it was not the wall. “If your theory’s right, we’re performing surgery on a mountain. How do you sedate a rock?”

“I don’t know.”

“Exactly,” she said, and then: “How long do you think we’ve been following this tunnel?”

“I—” He stopped. “I don’t know.”

“Neither do I.” She showed him her watch. “Either we’ve lived through the last hour three times over, or she’s adjusting time for reasons of her own.”

“Are we still on schedule?”

“I have no idea.” She stuffed the watch back in her pocket, not bothering to conceal her frustration. “What’s fast here might be slow out there, or the other way round. The mountain’s reflexes are fiercer near the wound. Which is why it’s good and bad we’re getting close.”

“You expect trouble?”

Which was when they turned the corner and saw the bone-thing.

“You could say that.”

Their goal lay at the tunnel’s end: the largest gallery yet, daylit almost with crystal and flame. Tara ignored that for the moment.

The bone-thing filled the tunnel mouth. Creaking, chattering, tangling and unwinding, it was no one shape entirely: an enormous bat’s skeleton propped with smaller bones, needle-sharp tail links of cave mice and translucent ribs from dead blind fish, a surface monster’s horned skull bleached by centuries. Wings tipped with curved claws flexed. Crimson lightning arced within the cage of its chest. Claw toes screeched chalk-white lines against the tunnel floor. Its jaw opened to roar, but no sound came.

Shale stepped forward, but she held out her arm to block him. “Surgery. No anesthetic. The more we fight down here, the worse it goes for us.”

He growled. She knew how he felt.

The bone-thing pounced. Claw wings filled the tunnel.

Tara closed her eyes.

Fractal silver schema rushed toward her, the bone-thing a story told by the mountain’s need. Tara’s first aesthetic reaction was contempt. If she had submitted such sloppy work at the Schools, she’d have spent a week helping golems dig up corpses to remind her the costs of brute force.

Her second aesthetic reaction, though, was pleasure. Such baroque profusion of power! The bone-thing was so dense she could barely see its individual strands. Crufty dynamism at its best. No calculating mind would make something so excessive. But the bone-thing was made, for a purpose, which you could see if you knew where to look—

Help me it hurts it hurts it HURTS—