The vault door section fractured inward with a sound like a cannon shot. Marcus was through the gap before the debris finished falling, ducking through the broken section at a run, coming up in the surface approach tunnel with the geological hammer raised—and stopped. Three mercenaries were directly in front of him, reaching for sidearms. Three more were at the seismic array control station, already turning.
Then Talon came through the vault door gap at full sprint. The mercenary nearest the gap made a sound that was not a professional response to tactical surprise but was instead the entirely understandable sound of a trained adult human encountering a three-meter feathered Cretaceous predator at close range for the first time. Two of the three mercenaries nearest the gap ran. Immediately. Without discussion.
The third—to his credit—held his position, which lasted approximately two seconds until Talon performed the full threat display: feathers fully erect, arms spread wide, sickled claws striking twin furrows in the basalt floor, and a sustained twenty-two-hertz resonance pulse at maximum amplitude that vibrated the air in the tunnel hard enough to feel it in the chest. The third mercenary reconsidered his professional obligations and ran after his colleagues.
The three at the control station were more organized. The commander—a compact woman in her forties with the bearing of someone who had managed genuinely dangerous situations before—had her team positioned at the seismic array controls rather than retreating, and she was not running.
"Dr. Vance," she said. Her voice was entirely level. "I am Commander Harrow, Vanguard Resource Corporation. You are interfering with a legally permitted geological survey."
"Your 'legally permitted geological survey,'" Marcus said, breathing hard, "has triggered a magma surge that is currently flooding the lower cavern system. You have destroyed an ecosystem that has been preserved in functional condition for sixty-five million years. And whatever extraction permits you think you hold, there is a federal paleontological preservation statute that supersedes every resource extraction claim when living fauna of the relevant geological era are discovered."
"You'd have to prove the fauna exists," Harrow said.
Talon stepped forward into the light of the control station, his amber-gold eyes reflecting the fluorescent work lights, his sixty-four-hertz echolocation pulse filling the tunnel with its deep subsonic warmth. Harrow looked at the raptor for a long moment.
"Or," Marcus said, "you could look at the twelve hours of acoustic, visual, and biological sample data on the drives in my vest."
Reyes and Patel came through the vault door gap behind him, both of them dust-covered and clearly exhausted, both holding their equipment packs.
"The magma surge is going to reach this level in approximately ninety minutes," Patel said, with the calm of someone delivering a geological report. "Commander, I would strongly recommend evacuating your equipment and personnel immediately."
Harrow looked at Talon once more. Then at the data drives. Then she began issuing evacuation orders.
The implosion circuit fired with a sound Marcus would spend years trying to adequately describe to students and journalists—not the sharp explosive crack of the seismic charges, but something denser and more final, like a door closing in the Earth's own architecture. He felt it in his jaw and his kneecaps simultaneously.
The rubble cascade that followed lasted eleven seconds and produced a dust cloud that rolled toward them down the tunnel in a slow, stately wave.
When it cleared, forty meters of passage had become a uniform wall of compressed rock and debris—effective, permanent, and tamper-resistant without specialized drilling equipment that would take weeks to mobilize. Marcus looked at Patel, who was already running his geological sensor along the edge of the collapse zone. "Structural integrity is good," Patel said.
"That's not coming open without a dedicated excavation team." He paused.
"Which Vanguard will absolutely attempt." "By which time we'll have the federal order filed," Marcus said.
Patel nodded. "Then we'd better get to the surface."