brightness, would tend to blind and so immobilize him. If retreat were
necessary, he would retreat: but it would be only a little less risky than
proceeding.
Janson unzipped his knapsack and removed the police radar detector. It was a
Phantom II, a high-end model meant for motorists who liked to speed and didn’t
like speeding tickets. What made it so effective was that it was both a detector
and a jammer, aiming to make a motorist’s car “invisible” to speed-detecting
equipment. It worked by detecting the signal and bouncing it back toward the
radar gun. Janson had removed its plastic casing, shortened the nub of its
antenna, and installed an additional capacitor, thus shifting its
radio-frequency spectrum to the microwave bandwidth. Now he used duct tape to
fasten the device near the end of the long telescoping steel rod. If it worked
as he hoped, he would be able to exploit an inherent design feature of all
outdoor security systems: the necessary tolerance for wildlife and weather. A
security system was useless if it regularly issued false alarms. Outdoor
microwave systems always used signal processing to distinguish human intruders
from the thousand other things that could cause anomalies in the signal—a branch
tumbling in the wind, a scampering animal.
Still, he was taking a stomach-plunging gamble. In less exigent circumstances,
he would have field-tested his hypothesis before staking his life on it.
One more time, he studied the configuration of the stanchions. The bistatic
sensors could be placed as far as seven hundred feet away from each other. These
were merely a hundred feet away—a spare-no-expenses approach that must have
gladdened whoever had been paid to install the system. And yet the proximity of
the sensors was another factor in Janson’s favor. The farther apart they were,
the broader the coverage pattern between them. At 250 yards, the coverage
pattern would swell to an oval that reached, at the midpoint between the two
sensors, a width of forty feet. At thirty yards, the coverage pattern would be
tighter and more narrowly focused, no wider than seven feet. That was one of the
things that Janson was counting on.
As he had expected, the poles along the second, staggered tier beamed to the
alternating pole in the tier closer to him, and vice versa. The point where the
two beams intersected, accordingly, was the narrowest possible area of coverage.
One stanchion was three feet to the left and two feet behind the other pole;
thirty yards to either side, the pattern was repeated. In his head, he drew an
imaginary line connecting the pair of adjacent stanchions, then the imaginary
line connecting the next pair. Midway between those two parallel lines would be
the point where the area of coverage was at its minimum. Janson moved toward
that point, or where he intuitively estimated it to be. Holding the steel rod,
he moved the Phantom II toward that spot. The system would have instantly
detected the appearance of an object, but it would also immediately determine
that the waveform patterns did not correspond to that of any human intrusion. It
would remain quiet and undisturbed—until Janson himself tried to cross. And that
would be the moment of truth.
Would the radar scrambler confuse the signal receivers, preventing them from
registering the presence of the very human intruder that was Paul Janson?
He couldn’t even be sure that the Phantom II was working. As a precaution,
Janson had disabled its displays; there would be no reassuring red light
indicating that it was mirroring the signals it received. He would have to
proceed on faith. He kept the Phantom II steadily in position, moving himself
down the pole, hand over hand, keeping it aloft without shifting its position.
Then he rotated the rod and continued to back away from the microwave barrier.
And … he was through.
He was through.
He was a safe distance on the other side. Which was not a safe place to be at
all.
As Janson walked toward the gently sloping fairway toward the mansion, he felt
the hairs on the back of his neck bristling, conscious on some animal level that
the greatest risks lay ahead.
He looked at the dimly illuminated LCD display of his black Teltek voltmeter,
holding it in cupped hands. It wasn’t field-caliber equipment, but it would do.
Nothing. No activity.
He traveled another ten feet. The digits began to climb; he took another step,
and they surged.
He was approaching the subterranean pressure sensors. Though the voltmeter
indicated that the buried cable itself was still a ways off, he knew that the
electromagnetic flux of TriStar’s buried-cable sensors created a detection field
that was more than six feet wide.
The rate of increase in the voltmeter’s display suggested that he was nearing
the active field. Nine inches beneath the sod, the “leaky” coaxial cable was
designed to have gaps in the outer conductor, allowing an electromagnetic flux
to escape and be detected by a parallel receiving cable that ran in the same
jacket. The result was a volumetric detection field around the coaxial cable,
about one foot high and six feet wide. Still, as with other outdoor
intrusion-detection systems, microprocessors were tasked with distinguishing one
kind of disturbance from another. A twenty-pound animal would not trigger an
alarm; an eighty-pound boy would. Intruder speeds, too, could be detected and
interpreted. Snow, hail, gusting leaves, temperature changes—all could alter the
flux. But the brains of the system would filter out such noise.
Unlike a microwave system, it could not be spoofed. The buried cables were
inaccessible, and the TriStar system had redundant tamper protection, so any
interruption of its circuits would itself be detected and prompt an alarm
response. There was only one way through it.
And that was over it.
Janson retrieved the telescoping rod and, twisting the segments
counterclockwise, locked it in its fully extended position. He walked some ways
back toward the microwave poles and, keeping the rod extended in his hands,
raced toward the buried sensor cables, imagining the invisible six-foot-wide
band to be a physical barrier.
He held the pole as he ran, then plunged the end of it in the ground, just above
where he believed the cable to be buried. Now: a step and drive. He swung his
right knee up and forward and jumped, swinging upward with his hips as he held
on to the pole. If all went well, his momentum would carry him, and he would
land a safe distance from the cable. It need not be a soaring, athletic pole
vault, but a broad jump; it was merely necessary to keep his body several feet
in the air. The volumetric detector would have been alerted only to the thin
pole twitching in the ground—nothing even approaching the volume, or flux
disturbance patterns, consistent with a human being. Now, as he kept his eyes on
the area of grass where he hoped to land, a comfortable distance from the buried
sensor cable, he suddenly felt the metal rod buckling under his weight.
Oh dear God, no!
In mid-arch, the rod collapsed and Janson tumbled heavily to the ground, just a
few feet from where he’d estimated the coaxial to lie.
He was too close!
Or was he? It was impossible to be sure, and the sheer uncertainty was the most
nerve-racking thing of all.
A cold sweat formed on his skin almost instantly as he rolled out of the zone.
Any moment now he would know if he had triggered the pressure sensors. The
floodlights would blaze; the camera would pivot. And then, as his visage came
into focus, a team of heavily armed guards would rush to the site. The
barricades and alarm systems to every side would make his chance for escape
essentially nil.
With bated breath, he waited, feeling relief budding with each passing second.
Nothing. He had cleared it. All three perimeter security systems were now behind
him.
Now he stood and looked up at the mansion that loomed before him. Up close, it
was breathtaking in its grandeur. To either side of the main house were vast
conical turrets; the exterior of the mansion was fashioned from Briar Hill
sandstone. The roof was trimmed with an intricate balustrade and topped with a
smaller one. The place was an eclectic display of architectural bombast. Yet did
it count as ostentation if nobody could see it?
The windows were dark except for a dim glow of what might be standard nighttime
illumination; were its inhabitants in the back rooms? It seemed too early for
anyone to be asleep. Something about the setup bothered Janson, but he could not
say why, and it was no time for turning around.
Now he crept to the left side of the building and over to a narrow side
entrance.
Mounted in the stone near the dark, ornately incised door was a discreet
electrostatic touch screen, of the kind used by ATMs. If the right numbers were