Yaut crossed the cabin, ears lowered, and bent over Kralik. His whiskers stiffened. “Yes, it is as we thought. Unharvesting indicates extermination. The Complete Harmony must be planning to come through this system and sterilize it.” He straightened, the line of his shoulders indicating worried-contemplation. “The Subcommandant has already communicated that probability to the Governor.”
“Then they’ll be ready,” Caitlin said. “We’ll be able to defend ourselves.”
“Harvesting is a ground operation,” Yaut said, “which we could defend against using the troops and materiel currently stationed on Terra. Unharvesting, or ‘weeding’ as it is sometimes known, is an assault on a planetary scale. The Complete Harmony will attack by discharging plasma in Terra’s atmosphere. Under those circumstances, tanks, artillery, and foot soldiers will be useless.”
“Then we’ll have to stop them out here,” Kralik said, “as soon as they emerge from the framepoint. We can’t let them get close enough to Earth to attack.”
Caitlin tried to think. “But Earth has very little in the way of a space fleet, just a few old shuttles, and I’ve been under the impression that most of the Jao ships from the initial conquest have been assigned elsewhere.”
“They have,” Aille said, “and long since.” His ears were canted very low. “The Ekhat press on many other fronts.”
She read cautious-indecision in his posture. Not at all reassuring.
“What about the submarines being refitted at Pascagoula?” Tully said from the far wall.
“Didn’t you see the size of that Ekhat ship?” Kralik said. “They would be too little, too late. The Jao need to bring back their heavy hitters.”
“We have no available ships large enough to be effective in that sort of warfare,” Aille said. “The vessels the Complete Harmony will bring will be as large as the one you just saw. Possibly larger.”
And that one had been huge, Caitlin thought.
“Earth still has missiles,” Tully said. “I think. Unless you Jao destroyed them all.”
“They won’t be any use.” Kralik shook his head grimly. “I understand now why the Jao have never spent any time developing missile weapons. You saw when that ship came through the framepoint. They wrap burning solar plasma around their hulls! Anything you shoot at them will be like tossing a match at the sun. A missile would be vaporized before it got anywhere near the actual hull. And what’s the point of setting off a thermonuclear device in what’s already a thermonuclear holocaust? As far as I can tell, you’d just be adding more energy to the plasma ball and making it worse.”
“Lasers are equally ineffective,” Aille said. “In the Jao experience, there is only one effective tactic against Ekhat ships using solar plasma weaponry. It is necessary to wait until the plasma ball has been discharged, when the ship will be vulnerable to lasers.”
“But what will happen to Earth if they release that much plasma in our atmosphere?” Caitlin asked.
“Temperatures in the exposed areas will rise rapidly,” Yaut said. “Combustible materials such as vegetal matter and building materials will burn. And there will be a rolling blast wave similar to that produced by some of your most powerful weapons.”
“You mean a hydrogen bomb?” Kralik stood and put an arm around Caitlin, who realized she was trembling. “This will be as destructive as a thermonuclear blast?”
“Similar, though not the same,” Aille said. “In some ways, worse. The amount of energy contained in one of those plasma balls greatly exceeds that of any nuclear weapon. At least, any that either Jao or humans have ever built. However, it is almost pure energy, with little of the contaminating radiation typically produced by nuclear weapons. Many of your species would survive the initial attack, therefore, especially if they have taken shelter below ground. Ultimately, though, if the Complete Harmony makes enough runs through the system, all of your kind would perish. So would all other forms of life on Terra. Enough of those fireballs will strip the atmosphere from a planet.”
“How many would die—the first time?” Caitlin heard herself ask, though she could have sworn she was too dazed to talk.
“Perhaps a twentieth or even a tenth of your population, if the Ekhat fleet is as large as usual.” Yaut said. “Even a single plasma fireball in the atmosphere can wreak havoc across much of a continent. It is difficult to predict. There are many variables and every world is different.”