d been assigned to
make sure that no such attempt would succeed with Colonel Mannheim.

He could see the length of the hallway that led to Colonel Mannheim's
suite. The hallway had been purposely designed for watching from the gun
tower. To one who was inside, it looked like an ordinary hallway,
stretching down the length of the building. But it was walled with a
special plastic that, while opaque to visible light, was perfectly
transparent to infra-red. To the ordinary unaided eye, the walls of the
building presented a blank face to the gun tower, but to the eye of an
infra-red scope, the hallways of all five floors looked as though they
were long, glass-enclosed terraces. And those walls were neither the
ferro-concrete of the main building nor the pressure glass of the
windows, but ordinary heavy-gauge plastic. To the bullets that could be
spewed forth from the muzzle of the heavy-caliber, high-powered machine
gun in the tower, those walls were practically nonexistent.

Captain Greer surveyed the hallways with his infra-red binoculars.
Nothing. The halls were empty. He lowered the binoculars and lit a
cigarette. Then he put his eyes to the aiming scope of the gun and
swiveled the muzzle a little. The aiming scope showed nothing either.

He leaned back and exhaled a cloud of smoke.

* * * * *

Colonel Mannheim blinked and looked at the ceiling. It took him a minute
to re-orient himself. Then he grinned rather sheepishly, realizing that
he had dozed off with his clothes on. Even worse, the pressure at his
hip told him that he hadn't even bothered to take his sidearm off. He
sat up and swung his feet to the floor, then glanced at his wrist. Three
in the morning.

_And the moral of that, my dear Walther_, he told himself, _is that a
tired man should put on his pajamas first, before he lies down and
drinks a Scotch_.

He stood up. Might as well put his pajamas on and get to bed. He would
have to be back in St. Louis by ten in the morning, so he ought to get
as much sleep as possible.

The phone chimed.

He scooped it up and became instantly awake as he heard the voice of
Captain Greer from the gun tower that faced the outer wall. "Colonel,
the Nipe is just outside the wall of your apartment, in the hallway. I
have him in my sights." He was trying to stay calm, Mannheim could tell
by his voice, but he rattled the words off with machine-gun rapidity.

Mannheim thought rapidly. Whate