ock wall. It crackled, spread, flaring to incredible heat and light.
It exploded, deluging the gallery with glare and spattering rock.

After the glare, darkness seemed thick enough to slice.

In that second of stunned reaction blindness, Denver was leaping the
barricade and sprinting toward the entrance. Caltis came to meet him.
Both fired at once. Both missed. The random beams flicked at the
rough, timbered walls and lashed out with thunderous violence.

Locked together, the men pitched back and forth. They rocked and
swayed, muscles straining. It was deadlock again. Denver was youth and
fury. Caltis had experience and the training of a fighter. It was
savage, lawless, the sculptured stance of embattled champions. Almost
motionless, as forces canceled out. The battle was equal.

V

While they tangled, both blocked, Darbor slipped past them and stood
outside the entrance. She was exposed, a clear target. But the men
below dared not fire until they knew where Caltis was, what had
happened to him. She held the enemy at bay. Gun ready, Darbor faced
down the slopes. It was not necessary to pull trigger. Not for the
moment. She waited and hoped and dared someone to move.

Neither man gave first. It was the weakened timbering that supported
the gallery roof. Loose stones rained down. Dry, cold and brittle wood
sagged under strain. Both wild shots had taken shattering effect.
Timbers yielded, slowly at first, then faster. Showering of loose
stones became a steady stream. A minor avalanche.

Darbor heard the sound or caught some vibration through her helmet
microphones. The men were too involved to notice. Caltis heard her. He
got a cruel nosehold, twisted Denver's nose like an instrument dial.
Denver screamed, released his grip. In the scramble, his foot slipped.
Darbor cried out shrill warning.

Breaking free, Caltis bolted in panic toward the entrance.

The fall of rock was soundless. It spilled down in increasing
torrents. Larger sections of ceiling were giving away.

Above the prostrate Denver hovered a poised phantom of eerie light.
Charley, bored, had gone to sleep. Awakening, he found a game still
going on. A fine new game. It was fascinating. He wanted to join the
fun. Like an angle of reflected light cast by a turning mirror, he
darted.

The running figure aroused his curiosity. Charley streamed through the
collapsing gallery. He caught up with Caltis just inside the entrance.
With a burble of insane,