THE southwest corner of the black fortress wavered in the scope image, its clean lines obscured by distance, a rapid-moving line of wispy clouds, and the distortion that came from the natural turbulence of Minkta's planetary atmosphere. From Defender Fifty-Five's synchronous orbit twenty-two thousand miles above the surface, Jims Harking reflected, there was a lot of distance and atmosphere to look through.

But the clouds, at least, he could do something about. He watched the image on his monitor, finger poised over the "shoot" button; and as the trailing edge of the cloud patch swept past, he gave the key a light tap.

And that was it for his shift. Four hundred and thirty high-magnification photos, covering the entire Sjonntae outpost and much of the surrounding terrain, all painstakingly set up and shot over the past eight hours.

As he'd done during his previous eight-hour shift. And the one before that, and the one before that.

Leaning tiredly back in his seat, Harking tapped the scrub key. The last photo, still displayed on his monitor, quickly sharpened as the sophisticated computer programs cleaned as much of the distance and atmosphere from the image as they could.

And with the scrubbing Harking now could see that there were also two figures in the photo, standing just outside the door at that corner of the fortress. Sjonntae, undoubtedly; the aliens never let the indigenous population get that close to their outpost.

Possibly looking up in the direction of the human space station high overhead.

Probably laughing at it.

Harking glared at the photo, trying to work up at least a stirring of hatred for the Sjonntae. But there was nothing there. He'd already expended all the emotion he had on the aliens, all the anger and hatred and fear that a single human psyche could generate. All that was left now was the cold, bitter logic of survival.

Perhaps that was all humanity itself had left. With a sigh, he touched the key that would send the scrubbed photo into the hopper with the rest of the shift's work. The analysts would spend their next shift poring over all of it, trying yet again to find a way through the damper field that protected the fortress from attack. A subtle pattern in Sjonntae personnel movements, perhaps, or some clue in animal activity that might indicate where the vulnerable whorl in the field might be located. Something that would help break the desperate war of attrition Earth found itself in.

Behind him, the door slid open. "Shift change, Ensign Harking," Jorm Tsu gave the official greeting as he stepped into the room. "I relieve you from your station."

"Shift change, aye," Harking gave the official response, pushing back his chair and standing up. "I give you my station."

Tsu stepped past him and sat down. "So," he said, the formalities concluded. "Anything new?"

"Is there ever?" Harking countered. "I saw what looked like a confrontation between an overseer and a group of slaves, and I saw a couple of Sjonntae outside the fortress who were probably giving us a one-finger salute. Otherwise, it was pretty quiet."

"Mm," Tsu said. "What happened with the slaves?"

Harking shrugged. "I don't know. By the time I finished the pattern and got back to that area, they were all gone."

"At least they weren't all lying there dead."

"Unless the survivors took the bodies away with them," Harking pointed out.

"Maybe," Tsu agreed. "But that would at least indicate the Sjonntae hadn't killed more than a third of them. It takes two live bodies to carry one dead one, right?"

Harking grimaced. The logic of survival. "Right," he conceded. "I didn't notice any drag marks either."

"Must not have been a really serious confrontation, then," Tsu concluded. "Either that, or the overseer was feeling generous today."

Harking shook his head, this time trying to work up some emotion for the hapless native beings down there who had been enslaved by the Sjonntae. But he didn't have anything left for them either. "There must be something we can send down to help them," he ground out. "Some kind of weapon that'll work in the middle of the Shadow field."

Tsu snorted. "Hey, you invent one and the war will be over in a week," he pointed out. "But what are you going to use? Technology's what draws the Shadows; and any weapon worth a damn against the Sjonntae will have to have some technology to it."

"I know, I know," Harking said, an edge of impatience stirring within him. Like everyone else in the Expansion, he'd gone over this whole thing a thousand times. Any weapon more advanced than a crossbow gathered the inexplicable, insubstantial Shadows around it. And in the presence of enough Shadow, sentient beings became desperately ill.

In the presence of more than enough Shadow, they died.

"What about explosives?" he suggested. "I seem to remember hearing a news report a while back about them using explosive crossbow bolts on Heimdal and Canis Seven. I never heard how it came out, though."

Tsu shrugged. "It worked fine for a time, only then the Sjonntae got explosives sniffers set up. They're probably still using them, at least off and on. Problem is, that kind of weapon only works against individual Sjonntae soldiers."

"Right," Harking said, the brief twinge of hope fading away. "And we don't care all that much about killing single Sjonntae soldiers."

"They care about it," Tsu said dryly. "But as far as breaking the stalemant goes, we need to find a way to take out the heavier stuff."

Harking nodded. The frustrating thing was that the Shadows didn't bother the technology itself. They could send a self-guided nuclear missile down to the surface, and even though every Minkter within miles of the thing would die from the concentration of Shadow it would quickly gather around itself, the missile itself would function just fine.

Only there would be nothing useful for the missile to do. The damper field went all the way to the ground, with only living beings able to pass through it.

So they couldn't send weapons or useful equipment to the Minkters. They couldn't break the Sjonntae damper field, either from orbit or from the surface, unless they could find the whorl, the one spot where the field was weak enough for human weaponry to destroy it. And they couldn't find the whorl.

And so the fortress sat there, filled to the brim with intact Sjonntae technology they would never be able to pull apart and examine and find a defense against.

The logic of defeat.

"By the way," Tsu added as Harking turned toward the door, "the commander said for you to drop by after your shift."

Harking frowned. "Did she say why?"

"Not to me," Tsu said. "She seemed a little on the grumpy side, though."

"Probably a bad photo or something," Harking said sourly. "Thanks."

Commander Chakhaza was in her office near the station's battle command center. "Ensign," she nodded a greeting as he knocked on the open door. "Come in."

"Thank you," Harking said, tucking his folded cap under his arm and coming to attention exactly two paces from her desk. Humanity might be doomed to destruction, but there was no reason to be sloppy while it was happening.

"At ease," Chakhaza said. "Sit down."

"Thank you," Harking said, pulling down the visitor's jump seat and easing into it. Chakhaza never let anyone sit while she was chewing them out, which implied this wasn't about some screwup on his part.

She also never went out of her way to be this courteous to the lower ranks either. That implied this might be good news. Either that, or very, very bad news.

"How'd the session go?" she asked.

"Pretty routine," Harking said. Apparently, she'd decided to ease into the main topic through a side door. "The weather was mostly clear. I got some good shots, I think."