The sky fell three hours later.
Kael was helping the refugees into the lower tunnels when the first shell hit. It wasn't explosive. It was a Seismic-Charge.
THOOM.
The entire mountain shook. Dust rained from the ceiling. A crack appeared in the granite support pillar of the main cavern.
"Structural integrity is failing!" Valerius shouted, rallying his men. "Seal the blast doors! Get everyone to the deep shafts!"
"They aren't landing," Elric yelled over the noise. "They're just softening us up!"
Kael ran to the observation slit.
Three Spire Battle-Cruisers hung in the sky above the canyon. They looked like floating cathedrals, bristling with magical cannons. Beams of focused light were hammering the mountain, turning the rock into molten slag.
"They're glassing us," Kael said. "They're going to melt the mountain on top of our heads."
"We can't fight ships!" Horg roared. "Our Striders can't aim that high!"
"We dig in," Valerius ordered. "We hold the lower levels. They have to run out of ammo eventually."
"They have the Refinery fuel," Kael reminded him. "They won't run out. Not before we suffocate."
Another impact shook the floor. The main entrance collapsed with a roar of tearing stone. Darkness swallowed the upper level.
Screams echoed from the refugee tunnels.
"We're dead," a soldier whimpered, dropping his spear. "We're rats in a trap."
Kael looked at the ceiling. He felt the vibration of the bombardment in his bones. But he felt something else, too.
A resonance.
Deep below them. Deeper than the mine.
The Void-arm was humming.
"Elric," Kael said, grabbing the scholar. "The maps. The old survey maps of this mine. Show me the lowest level."
"The lowest level?" Elric fumbled with his scrolls. "It's just the 'Boneyard'. Dead ends and strange calcified rock. Why?"
"It's not rock," Kael said. He remembered the shape of the tunnels. The curve of the walls.
"Valerius! Hold the line!" Kael shouted. "I'm going down!"
"There's nothing down there!" Valerius yelled back.
"There's a gun," Kael said. "A big one."
He sprinted towards the service elevator, diving into the shaft just as the upper gantries gave way.