The Seventh Angel

cameras, and music players. This new technology is too difficult to keep track of. Nearly anything might be used to send an email message or make a phone call.”

He shifted his eyes back to the park. The snow was falling faster now, nearly obscuring his vision of Lenin’s statue. In another day, maybe less, the secret would be out. All eyes would turn to this obscure little smudge on the face of the globe, and the world would rediscover the true power of Russia. But the secret must keep for a few more hours.

The world had taught itself to fear little men, with little bombs, and the insignificant dreams of insects. This they had labeled terror. The very word brought a mirthless smile to Sergiei Zhukov’s lips. The world had forgotten what terror really was. But it was about to remember.

CHAPTER 10

MOUSE (MULTI-PURPOSE AUTONOMOUS UNDERWATER SYSTEM)

NORTHERN PACIFIC OCEAN (SOUTH OF THE ALEUTIAN ISLANDS)

TUESDAY; 26 FEBRUARY

1021 hours (10:21 AM)

TIME ZONE -10 ‘WHISKEY’

In technical terms, Mouse was experiencing a third-order heuristic non-parity as a function of suboptimal iterative taxonomic indexing. In plain English, the robot was confused. It had reached the designated navigational coordinates, performed a detailed sensor survey of the area as specified by its current mission program, and located an object that closely matched the identification criteria for its target.

The object under examination was approximately the correct shape (nominally ellipsoid with dorsal and ventral protrusions), approximately the correct size (7.924 meters in the major axis, and 2.438 meters in the minor axis), and closely located to the center of the designated search grid (31.626 meters from grid reference zero). Based upon these factors, and the lack of any other remotely qualifying objects within the perimeter of the search grid, Mouse’s onboard computer had labeled the object as “Presumptive Target #1,” and assigned a confidence factor of 98.2 %. Mouse was 98.2 % certain that Presumptive Target #1 was the object that it had been sent to locate.

None of this had been difficult for Mouse. These were exactly the sorts of evaluations and decisions that the robot made best. The problem was mud. Mouse didn’t know anything about mud, and that lack of knowledge was interfering with the robot’s ability to make a critical decision.

The next phase of the mission required Mouse to identify a loop-shaped fixture on the upper surface of Presumptive Target #1. Mouse had located a fixture near the designated area of the object. Using physical location as a primary criterion, the fixture was a high-confidence match, after correcting for variations in spatial orientation. Presumptive Target #1 had approximately 12.5 degrees of y-axis rotation and 30.0 degrees of z-axis rotation, but — corrected for that — the candidate fixture had a location confidence factor of 99.8 %.

The problem lay in the shape of the fixture. Mouse’s mission program queue contained a detailed digital model of the fixture the robot was programmed to identify. And the fixture at the specified location was not a good match for the model, only 41.2 %. It was in the correct place and was roughly the correct size, but it was not the correct shape.

The fixture had a name. It was a lifting shackle. And, as Mouse had been advised, it was loop-shaped. Unfortunately, the lifting shackle was packed with mud, compliments of its encounter with the sticky sediments of the Aleutian Island slope during the accident that had put the submersible Nereus on the bottom of the ocean.

Had Mouse known about the mud, the robot could have completed its identification of the lifting shackle, and moved on to the next phase of its mission: locating the lifting cable that the Research Vessel Otis Barton had lowered into the ocean. The phase after that, connecting the Otis Barton’s cable to the Nereus’s lifting shackle, would not be difficult at all. But to get there, Mouse had to correctly identify the lifting shackle, hiding under several layers of Aleutian Island mud.

Mouse wasn’t aware of any of these things. It had not been told that the fixture had a name. It didn’t know that Presumptive Target #1 was the deep water submersible Nereus, or that the three human beings inside the submersible were either dead or dying. Mouse didn’t even know what a deep water submersible was. The robot only knew that it was at the correct geographic coordinates, hovering five meters away from an object that closely matched its search criteria, evaluating a candidate fixture that was not the correct physical shape.

The situational-response algorithms built into Mouse’s core programming decided to examine the puzzling fixture from another position. With measured surges from its maneuvering thrusters, the robot moved ten meters to the East, and swung its nose a corresponding amount to the left, so that it faced the object from a different angle.

When the maneuver was complete, the candidate fixture was once again centered in the cone of light cast by Mouse’s sealed Halogen lamps. Satisfied with its new position, the robot studied the illuminated fixture through a pair of high-resolution video cameras. The results were no more satisfactory. The fixture was still the wrong shape.

Once again, the situational-response algorithms did their work. The computer shut off the robot’s Halogen lamps to minimize optical interference, and triggered its LIDAR scanner for a more detailed look at the improperly-shaped object. Short for Light Imaging Detection And Ranging, LIDAR was similar to radar, except that it transmitted and received low-intensity laser light instead of microwaves. The LIDAR scanner mounted on the upper leading edge of the robot’s hull directed a burst of laser light toward the presumptive target. In the space of one second, the scanner emitted 400 pulses of high- frequency laser light in a clockwise reticulated-rosette scanning pattern, and recorded and evaluated the resulting reflections.

The wavelength of the laser was tuned to 495 nanometers, in the blue-green band of the optical spectrum, the frequencies least likely to be refracted and absorbed by water. The individual laser transmissions were timed so closely together that a human eye could not have distinguished them as discrete events. A human observer — had one been present — would have seen only a second of flickering blue-green light.

The LIDAR scanner completed its transmission sequence. The laser went dark, and the Halogen lamps snapped back on to provide illumination for the video cameras as the robot processed and assembled images from the laser scan.

The detailed LIDAR images revealed nothing new. The candidate fixture was still the wrong shape.

The cognitive architecture that formed the core of Mouse’s operating program was designed to continue functioning in the event of one or more logical failures. In computer-speak, this concept was called fault tolerance, or graceful degradation. Had the graceful degradation software been correctly coded, Mouse would have been able to override the programming conflict and continue its mission. But there was a bug in the program code. When the graceful degradation loop was triggered by an error, it was supposed to activate a subroutine to record the nature of the mistake for future correction, and then bypass the error to continue functioning. Instead, the faulty program activated the emergency maintenance subroutine, erroneously informing the robot that it had sustained critical damage, and ordering it to return to the surface for repair. This was the software bug that Mouse’s programmer, Ann Roark, had been chasing, and it wasn’t corrected yet.

Faced with an insolvable logical conflict — this fixture on the upper surface of Presumptive Target #1 must be the one specified, but this fixture cannot be the one specified — Mouse’s core program activated the graceful degradation routine. The faulty software responded by triggering the emergency maintenance subroutine.

The robot’s computer immediately noted the damage signal and prepared to abandon its mission and head for the coordinates it had been launched from.

Without Ann Roark’s middle-of-the-night tinkering, the rescue of Nereus would