end of the corridor a snub-barreled robot gun was
maneuvering into position. A siren wailed. Guards were running on all
sides, hurrying to battle stations.

The robot gun opened fire. Part of the corridor exploded, bursting
into fragments. Clouds of choking debris and particles swept around
them. Reinhart and his police retreated, moving back along the
corridor.

They reached a junction. A second robot gun was rumbling toward them,
hurrying to get within range. Reinhart fired carefully, aiming at its
delicate control. Abruptly the gun spun convulsively. It lashed
against the wall, smashing itself into the unyielding metal. Then it
collapsed in a heap, gears still whining and spinning.

"Come on." Reinhart moved away, crouching and running. He glanced at
his watch. _Almost time._ A few more minutes. A group of lab guards
appeared ahead of them. Reinhart fired. Behind him his police fired
past him, violet shafts of energy catching the group of guards as they
entered the corridor. The guards spilled apart, falling and twisting.
Part of them settled into dust, drifting down the corridor. Reinhart
made his way toward the lab, crouching and leaping, pushing past heaps
of debris and remains, followed by his men. "Come on! Don't stop!"

* * * * *

Suddenly from around them the booming, enlarged voice of Sherikov
thundered, magnified by rows of wall speakers along the corridor.
Reinhart halted, glancing around.

"Reinhart! You haven't got a chance. You'll never get back to the
surface. Throw down your guns and give up. You're surrounded on all
sides. You're a mile, under the surface."

Reinhart threw himself into motion, pushing into billowing clouds of
particles drifting along the corridor. "Are you sure, Sherikov?" he
grunted.

Sherikov laughed, his harsh, metallic peals rolling in waves against
Reinhart's eardrums. "I don't want to have to kill you, Commissioner.
You're vital to the war: I'm sorry you found out about the variable
man. I admit we overlooked the Centauran espionage as a factor in
this. But now that you know about him--"

Suddenly Sherikov's voice broke off. A deep rumble had shaken the
floor, a lapping vibration that shuddered through the corridor.

Reinhart sagged with relief. He peered through the clouds of debris,
making out the figures on his watch. Right on time. Not a second late.

The first of the hydrogen missiles, launched from the Council
buildings on the o