Chapter 149: The Wrong Beacon
Wren crouched beside the residue without touching it.
"Colby. Lamp."
Ren held the beam steady.
Jin was already three meters farther up the passage, holding the sealed sample case and looking between it and the wall.
Pale crystalline growth cut from a seam at marker five, sealed inside a case. Pale crystalline dust coating the walls wherever something had scraped deep gouges through the stone.
"Wren."
"I see it."
"No, I—" Jin stopped and made himself report it properly. "I might have something. It’s a low-confidence guess, and I want to say it out loud before it gets any better, because you told me to."
Wren stood.
"Go."
"Back at marker five, you cut the sample. About four minutes later, the thing underneath us changed direction."
Nobody spoke.
"Say the rest," Wren said.
"I’ve been tracking its heading whenever Glitch has the sense open. It went north, then east, then north again. It doesn’t move in a straight line. It wanders." Jin raised the case. "But it wandered toward us right after the seam was opened, and there’s crystal dust on these walls wherever something has been scraping the rock."
"Tally."
The fennec already had her nose inside one of the gouges. She worked along it for several seconds, crossed to a second mark four meters away, then found a low burrow mouth in the far wall that Jin had missed completely.
Wren lowered the case toward her. Tally sniffed around the outer seal, where faint residue from the original cutting remained, then returned to the gouge and made a short sound.
"Same mineral scent in all three," Wren said. "Matches the sample."
"So it eats rock," Dolan said.
"It eats that rock," Jin replied. "Maybe. That’s still a jump, and I know it is."
Wren looked from the case to the black passage ahead, then at the four students standing inside a route nobody had mapped.
"How would you test it?"
"Put the case against connected stone and see whether the thing changes direction. Lift it away and see whether it loses the line."
"And if it comes straight toward us?"
"Then we learn something," Jin said, "and we run."
"That’s an unpleasant answer."
"It’s the true one."
Wren took the brief pause she always seemed to need before committing.
"Two tests. No more. Everyone stays packed and standing." She pointed across the passage. "Reyes, take Ash to the far side. You do not attack anything. You cover the retreat. Colby, Anvil holds the fracture mouth. If this goes wrong, we leave the way we came. Astor, run the test and do it quickly."
They moved into position.
Jin placed the sealed case flat against a bare shelf of connected stone, stepped back four meters, and rested a hand on Glitch. Through the bond, he directed the lizard’s attention down into the surrounding rock.
Tremor Sense opened. Glitch settled into that particular stillness.
For eleven seconds, nothing changed.
Then a heavy pulse rose through the stone, followed by another. The movement had been traveling across the deeper layers at an angle. The next step landed differently, shifting toward the shelf beneath the sample.
The impression reached Jin through the bond in its simplest possible form: something heavy had been moving one way, and now it was moving another.
Toward them.
"It turned," he said. "It’s coming. High confidence."
"Off," Wren ordered.
Jin snatched the case from the shelf and held it against his chest. The four of them waited in the dark like passengers expecting a tram.
Twenty seconds passed.
"It’s slowing," Jin reported. "Not stopping. It’s wandering again. It lost the direction."
"Second test."
They repeated the experiment forty meters farther along the passage. The thing turned again, and this time the response came faster.
"That happened sooner," Jin said. "Which I think is worse."
"That’s enough," Wren said. "Nobody needs a third test."
She took the case and turned it over in her hands.
"It isn’t hunting us."
"I don’t think it has noticed us as people," Jin said. "Noise, maybe. We opened a vein it was already working toward and made the mineral fresh."
From behind Anvil, Ren spoke in a very small voice.
"So we did this."
"No," Wren said immediately. "The academy sent us in with a survey that marked this entire section as solid stone. Either the creature arrived after the survey or the survey missed it. We followed the mission exactly as written. This is not on us."
Her voice stayed flat and steady, and Jin watched Ren straighten by a couple of centimeters.
Wren checked the case seal and began walking again.
"Astor. Find me a dead end."
Jin found one for her two hundred meters farther along.
A narrow branch split from the main passage, ran twelve meters, and ended in unbroken rock. Glitch confirmed that the floor remained connected stone all the way back to the junction.
Wren carried the case to the far end. She cracked the seal just enough to expose the mineral and strengthen whatever scent or signal the creature had followed during the tests, then set it directly against the floor.
Dolan made a noise behind her.
"Say it," Wren said without turning.
"That’s the objective."
"It was."
"We got it." Dolan was not shouting. That was the thing Jin kept noticing about Dolan Reyes: he ran hot, but he did not run stupid. "That’s the one thing on the sheet we actually finished. We reached marker five, cut the sample, sealed it, and now we’re leaving it in a hole."
"Point five," Wren said.
"I know point five."
"Then say it."
Dolan breathed out through his nose.
"Withdraw if conditions don’t match."
"The fifth line overrides the first four. Withdrawal matters more than collection." Wren stood and faced him. "And I’m not throwing the sample away. I’m using it. While we carry it, it’s a beacon attached to us. In here, it’s a beacon twelve meters off our route, pointing the wrong way."
Dolan looked at the open case for a moment.
"Fine," he said. "It’s still stupid that it works like this."
"It’s completely stupid," Wren agreed. "Move."
The system they used afterward was simple enough that even Jin, who generally resented systems requiring him to stand, thought it was good.
Tally chose the route. She followed airflow and scent, checked which openings continued, and judged which holes actually had floors. She was better at it than anything Jin could have accomplished with a phone.
Glitch handled what Tally could not smell: movement, weight, and whether the ground ahead was one connected mass or several unstable sections pretending to be one.
Over the last four hours, Jin had become faster at translating what came through the bond than he had during all the weeks since Glitch hatched. He could wait until he fully understood an impression, or begin reporting while it was still taking shape.
Down here, only the second option was useful.
Wren chose the route and controlled the pace.
Anvil entered first whenever the passage narrowed. Ash remained at the rear, cold and ready, and Dolan complained about that exactly once.
Nine hundred meters into the unrecorded route, the crawlers found them.
They were the same pale creatures that had attacked from the ledge between markers three and four: long, all limbs, their bodies coated in a chalky sheen. The survey identified them as ceiling-dwelling ambush predators, matching the earlier encounter.
It had not recorded this many packed into the uncharted fractures. Something larger had likely driven them upward.
They emerged from ahead and below, spilling from side cracks into a passage barely two and a half meters wide.
There were far more than three this time.
"Choke," Wren said. "Colby, thirty meters back. The narrow section with the shelf. Go."