Melissa hesitated, but Eachan broke in, almost hastily. Good idea, girl," he said, almost gruffly. "Why don't you do that? Do you good to get out for a change."
The tone of Eachan's voice made his words sound like a command. But the naked voice of appeal could be heard beneath the brusqueness of the words. Melissa surrendered.
"Thank you," she said, raising her eyes to meet those of Cletus, "that sounds like fun."
10
Stars were beginning to fill the Bakhallan sky as Cletus and Melissa reached the gates to the Navy Yard and were met by an ensign attached to Wefer Linet's staff. The ensign conducted them inside to the ramp where the massive, black, two-story-tall shape of a Mark V squatted on its treads just above the golden-tinged waters of the Bakhallan harbor. Cletus had phoned Wefer immediately on parting from Eachan and Melissa to set up the evening's excursion.
Wefer had been enthusiastic. Navy regulations, he gleefully informed Cletus, absolutely forbade his allowing a civilian such as Melissa aboard a duty Navy vehicle like the Mark V. But, personally, he did not give a damn. For the record, he had caught only the words "Dorsai" and "Khan" when Cletus had phoned him earlier - and to whom, of course, could those words apply but to a mercenary colonel of his acquaintance, who was certainly no civilian? So he would be waiting for Colonel Grahame and Colonel Khan aboard the Mark V at 7 P.M.
Awaiting them he was. Moreover, he seemed to have shared the joke of his little deception of Navy regulations with his under-officers and crew. The ensign meeting Cletus and Melissa at the Navy Yard gate had gravely addressed Melissa as "Colonel"; and they were hardly aboard the Mark V before three of the seamen, grinning broadly, had found occasion to do the same.
This small and ridiculous joke, however, turned out to be just the straw needed to break the back of Melissa's stiffness and reserve. On the fourth occasion of being addressed as "Colonel," she laughed out loud - and began from then on to take an honest interest in the outing.
"Any place in particular you'd like to see?" asked Wefer, as the Mark V put itself into motion and rumbled slowly down its ramp into the bay.
"Up the river," said Cletus. "Make it so, Ensign."
"Aye, sir," said the ensign who had met them at the gate. "Balance all tanks fore and aft, there!"
He was standing at the con, a little to the left of Wefer, Cletus and Melissa, who were placed before the large, curved shape of the hemispherical screen, which looked through the muddy water ahead and about them as though it were clear as glass, to pick up the shapes of ships' undersides and other solid objects below water level in the harbor.
There was a faint hissing and rumbling noise all around them. The vibration and sound of the heavy treads on the ramp suddenly ceased, and the water line shown on the hemispherical screen moved up above the horizon mark as the huge vehicle balanced out its ballast, replacing water with compressed air where necessary, and vice versa, so that the submarine dozer - its hundreds of tons of land weight now brought into near balance with an equal volume of water - floated as lightly as a leaf in air down to the muddy bottom of the harbor, sixty feet below.
"All forward, right thirty degrees horizontal," ordered the ensign; and they began their underwater tour upriver from Bakhalla.
"You'll notice," said Wefer in the fond tone of a father pointing out the talents of his first newborn, "our treads aren't touching the bottom here. There's nearly ten feet of loose silt and muck underneath us before we hit anything solid enough for the Mark V to walk on. Of course, we could settle down into it and do just that, if we wanted to. But why bother? We're as much at home and a lot more mobile to staying up in the water itself and simply swimming with the treads... Now look there... "
He pointed to the screen, where, some two hundred yards ahead of them, the bottom dipped abruptly below their level of sight for a space of perhaps fifty yards before it rose again.
"That's the main channel - the main current line to the sea," Wefer said. "We clean that out daily - not because there're any ships here with draft enough to need a hundred and ten feet of water under them, but because that trench provides a channel for the current that helps keep the harbor from silting up. Half of our work's understanding and using existing patterns of water movement. By keeping that channel deep, we cut our normal silt-removal work in half. Not that we need to. It's just the Navy way to do it as efficiently as possible."
"You mean you've got enough Mark V's and crews to keep the harbor clear even if the channel wasn't there?" Cletus asked.
Wefer snorted good-humoredly. "Got enough... " he echoed. "You don't know what these Mark V's can do. Why I could keep the harbor clean, even without the current channel, with this one machine alone!... Let me show you around here."
He took Cletus and Melissa on a tour of the Mark V's interior, from the diver's escape chamber down between the massive treads to the arms turret at the top of the vehicle, which could be uncovered to allow the Mark V to fire either its two heavy energy rifles or the underwater laser with which it was provided.
"You see why Traynor wanted these Mark V's for use in the jungles," concluded Wefer, as they ended their tour back in the control room before the hemispherical screen. "It hasn't got the fire power of the Army's jungle-breaker tanks, but in every other respect, except land speed, it's so far superior that there's no comparison - "
"Sir," interrupted the ensign behind him, "deep-draft surface vessel coming down the channel. We're going to have to get down and walk."
"Right. Make it so, Ensign," answered Wefer. He turned to the screen and pointed at the V-shaped object cutting the line of the river surface some two hundred yards ahead of them. "See that, Cletus?... Melissa? It's a boat drawing nine or ten feet of water. The channel here's less than fifty feet deep and we're going to have to get right down on the bottom to make sure that boat goes over with a good couple of fathoms of clearance."
He squinted at the V shape growing on the screen. Suddenly, he laughed. "Thought so!" he said. "That's one of your river patrol boats, Cletus. Want to have a look at its topside?"
"You mean, with a sensor float?" asked Cletus, quietly.
Wefer's jaw dropped. "How'd you know about that?" he demanded, 'staring.
"There was an article about it in the Navy-Marine Journal a little less than two years ago," answered Cletus. "It struck me as the sort of device a sensible navy would put aboard a vehicle like this."
Wefer still stared at him, almost accusingly. "Is that so?" he said.
"What else about the Mark V do you know that I don't know you know?"
"I know that with a bit of luck you might be able to capture a boatload of Neulander saboteurs and supplies bound for Bakhalla tonight, if you want to try for it. Have you got a map of the river?"
"A map?" Wefer lit up. He leaned forward and punched buttons below the hemispherical screen. The image on it vanished, to be replaced by a map showing the main river channel with its tributaries from the harbor mouth at Bakhalla to some thirty miles upstream. A barely moving red dot in the shape of a Mark V seen from above was crawling up the main channel in representation of the vehicle enclosing them. "What guerrillas? Where?"
"About six kilometers upstream from here," Cletus answered. He reached out to point with his forefinger to a spot ahead of the small, red, moving shape of the Mark V, where a tributary almost as large as the main river joined it at that spot. Up beyond the point of joining, the tributary spread itself out into a number of small streams and then marshland.
"There's an unusually high tide tonight, as you know," Cletus said. "So from this point on down there will be at least an extra eight feet of water in the main channel. Enough extra depth so that any small upriver motor launch could make it down into Bakhalla harbor towing a good load of supplies, and even personnel, behind it, safely underwater in a drogue pod. It's just a guess on my part, of course, but it hardly seems to me that the guerrillas would let a chance like this slip by without making an effort to get men and supplies to their people in the city."