Brande had already set the switches for control of Atlas, and he used the left stick to ease in propulsion for the ROV. He flicked on the robot’s video camera and put the image on the left monitor, then turned on Atlas’s floodlights. He had a view of the underside of DepthFinder for a few seconds until the ROV moved out of her sheath and took flight on her own. A quick look at the monitor gauge told him that the tether was unreeling freely behind the robot.
“Find that acoustic channel they’re using for voice, Kim,” he said. “We won’t know what they’re saying, but maybe you can tell if the tempo picks up.”
“I’ve got it,” she said.
Brande’s and Dokey’s headsets were tuned into the ship-to-sub channel on the Loudspeaker system, though they had not utilized them in the last hour. Otsuka was listening in on AquaGeo’s frequency.
“Sonar shows no subs in the area,” Dokey said. “if you don’t count us.”
“I don’t know how many they had available before,” Brande said, “but we know for damned sure that they’re short one, right now.”
Dokey put the bow down, and they glided. A few minutes later, the huge excavation appeared in the ports. Both the left and right edges of the hole were invisible, hidden by the darkness creeping into their lighted field of view. The far side wasn’t yet visible to them, either.
“Larger than the last one,” Dokey said.
“They’re using more horsepower in those nuclear charges,” Otsuka guessed.
“Which is just what we didn’t want them to do,” Brande said. “I wonder if anyone from Washington is actually talking to anyone from AquaGeo.”
“I’d bet it’s still in committee, Chief.”
Dokey sailed over the near-side lip of the excavation, heading directly across it. Several seconds went by before they saw the other side.
And the floor crawler.
It was parked right at the edge, its manipulator arm fully extended as it gathered rock samples, lifting them into a collector basket mounted on the front of the crawler, between the tracks.
If they had been so busy with their chores that they weren’t watching their sonar, the crewmen inside were now aware of them. As he watched, the manipulator arm retracted and the crawler backed quickly away from the lip of the hole, turning away from them.
Dokey went into a right bank, aiming to circle around and come in behind the crawler.
Brande had discussed their tactics on the way down, allowing Otsuka to overhear. He had worried that she might object, but she had wholeheartedly endorsed the strategy Brande and Dokey had devised.
“He’s going to hightail it,” Brande said. “Headed for the garage.”
“The garage is damned far away,” Dokey said, straightening out his sticks and bringing DepthFinder into line directly behind the scampering crawler.
The crawler dodged around a giant outcropping, but returned to a course of 205 degrees.
“His heading is directly toward that sea habitat,” Otsuka said.
“He’s making fourteen knots,” Brande told Dokey. “I’d guess that’s his top end on the level.”
“I can out-drag him.”
The submersible was making sixteen knots, her twin electric motors spinning fast enough to create a whining vibration in the hull.
Brande watched through his port and saw the back end of the crawler drawing closer. It was in silhouette, outlined by the powerful lights on the front end. The view was hypnotic. He felt as if he could reach through the porthole and touch the crawler. Small clouds of silt rose behind each of the massive tracks as they spun their way across the seabed.
And ahead of him by thirty feet, Atlas shot along above the seafloor, responding instantly to the signal inputs of the joysticks.
“He’s watching us,” Dokey said.
On top of the crawler’s spherical hull was a nest of antennas and a remote-controlled video camera. The camera was aimed at them.
“Be careful of the antennas, Dane,” Otsuka cautioned.
“Roger, Kim.”
Brande didn’t intend to damage their communications ability. He wanted them to be able to get a message out. They could send for help, but the message was important, too.
The gap between them closed.
Brande switched his attention to the view on the screen from the ROV. Atlas had closed to within ten feet of the crawler, which was bouncing up and down as it traversed the rugged terrain. On the screen, he watched it jolt into a large depression, and then bounce back out of it. The ROV slid along smoothly behind it, disappearing into the cloud raised by its passage.
The monitor view was hazy for a moment as Atlas passed through the roiling silt. The ROV advanced on the center of the crawler, between the tracks, and the view cleared enough to show him the big induction motors mounted low and behind the crawler’s hull, between the tracks. Each motor drove a transmission attached to it which directed power to each of the tracks.
“See anything vulnerable, Okey?”
After a quick look at his screen, Dokey said, “I’d try for those armored cables coming out of the motors, Chief. You only need one, and he goes in circles forever.”
“We’re going to have to change our design thinking in the future,” Brande said. “We didn’t anticipate trying to maneuver both Atlas and her manipulator arm while on the move.”
“We don’t usually go after moving objects,” Dokey said. “Not too many objects move down here.”
The crawler driver decided to participate in his own destruction. Apparently worried about his exposed rear, he slammed on the brakes and went into a left turn.
Dokey reversed motors so as not to over-shoot him, and Brande turned the ROV to follow the crawler, slowed her to a stop, and shifted his hands to the manipulator controls. On the screen, he saw the arms shoot out directly ahead of the robot, into the field of view of the video camera.
He quickly eased in power, moved the robot ahead, went back to the manipulator, and clamped the thumb-and-two-fingered hand over the thick cable exiting from the left motor. It was only about a two feet long, reaching from the motor into a control box.
With the hand clamped in place, the crawler would never lose him now. As long as Brande wanted, Atlas was now a trailer for the floor crawler. He glanced out the port and saw the crawler’s video camera moving frantically, attempting to angle down, trying to see what was happening.
The crawler driver threw power to the right track, spinning in place, trying to move his own manipulator into position to protect himself.
“Somebody’s talking up a storm on their acoustic channel,” Otsuka reported.
Dokey backed away from the crawler and its flailing manipulator arm, but Atlas hung on to the aft end.
Brande watched his screen and extended the tool hand. It had a cutting torch in place.
He fired the torch.
Reached out, put the flaming torch next to the armored cable, and watched as flexible metal turned molten, superheated, and then froze white in the chill of the sea. Big droplets of shapeless metal dripped slowly out of the camera’s view.
The crawler stopped turning.
The cable parted.
“Good show,” Dokey said.
Brande released the robot’s grip, then backed her away, making certain he kept the ROV clear of the machine’s big manipulator.
The crawler tried to go somewhere. It started and stopped, but only the right track would move, and it spun in place, like a child’s broken toy. And no one was going to get out and change the tires.
“You suppose he’s cussing us, Chief?”
“He would be,” Otsuka said, “if I could interpret the acoustic channel.”
“The best part, Okey, is they’re going to have to bring in support ships and raise him to the surface to make repairs. That takes time.”