Jack Campbell: Leviathan

But with the dark ships only five hours’ travel time from the hypernet gate, Geary frowned as a sudden thought came to him. “Tanya.”

She was still on the bridge as well, of course, looking totally unruffled by the hours spent up here. “Yes, Admiral?”

“Suppose I were commanding those dark ships—”

“As best we know, the artificial-intelligence routines running them are based on what you’ve done,” she pointed out.

“Exactly.” Geary pointed at his display. “I know I’m being pursued. I know that if I flee through the hypernet gate, I will reveal the place where my base is located, allowing the enemy to attack it and cut off my entire fleet at the knees. What do I do?”

Desjani frowned as well. “You? You sure as hell don’t use the gate. Not you.”

“No.” Geary sat up straighter, glaring at his display. “I realize that I can’t get away without betraying the rest of my fleet, so I have to stay here, and since that means being destroyed, I have to do whatever damage I can here before all of my ships are lost.”

She stared at him, then focused on her display, hands flying as she tested courses and actions. “Ancestors preserve us. They’re going to go for Ambaru, aren’t they?”

“Yes. If we keep charging after them, and they turn aside from the hypernet gate at the last moment and head for Ambaru, we won’t even see the maneuver for nearly three hours. My battle cruisers won’t be positioned to be able to intercept them before they reach the station and blow apart the central command-and-control node for this star system.”

“Why not just throw some rocks at it?” Desjani demanded, using the fleet nickname for kinetic bombardment projectiles, which really were little more than smoothed hunks of metal. “No one could—They’ve run out, haven’t they?”

“Yeah,” Geary said. “I think so. They used up their rocks beating the hell out of every possible target at Indras and Atalia. So they get us out of position chasing them, then charge at Ambaru and take it out at short range with their hell lances. They’ll know exactly what to target on the station.”

Her expression hardened into anger. “Because they’ll have blueprints for every ship and station. Because the Alliance government was so worried about internal threats, it assumed its own military installations might have to be potential targets.”

“That’s what I think,” Geary agreed, studying his display. “But if I’m right, we’ve still got time to mess up their plans. It won’t be easy, though. I can move battleships to blocking orbits, but against something as maneuverable as the dark ships, that may not be enough.”

“Focus on countering what you would do,” she reminded him.

That required thinking a bit backwards. First, using the simulator on his display to figure out how to best position the battleships that could reach blocking orbits in time. Then, shifting perspective to look at those battleships and try to figure out the best way past them to reach Ambaru. It was as difficult, and as unsatisfying, as playing chess against himself. “Tanya, there’s something wrong with this.”

“What?” She leaned over, eyeing his display.

“Those dark ships are programmed to do what the programmers thought I would do, not what I would actually do,” Geary explained.

“Not entirely. They based a lot of it on the battles you’ve actually fought. But I get your point,” Desjani admitted. “You have to think like Black Jack the hero of legend as they think he is, because that’s also who the dark ships will be thinking like. So what does the great hero do here?”

He took another look at the dark ships. Two battle cruisers, one heavy cruiser, and five destroyers. Then at his plans to defend Ambaru. There were twenty-one battleships left in his First Fleet. Several of those were laid up undergoing major repairs. Several more were not in orbits that would allow them to move to block the dark ships in time. That left seven battleships he could get into blocking orbits in time to meet the dark ships if they headed for Ambaru— Warspite , Vengeance , Resolution , Redoubtable , Colossus , Amazon , and Spartan . There would also be several divisions of light cruisers and destroyers, but the battleships would form the armored shield for the defense.

“Admiral Geary,” he said slowly to Desjani, “me, that is, would swing wide and either up or down, outmaneuvering the blocking force and getting to Ambaru before the battleships could have any hope of lumbering into new positions.”

“What would Black Jack do?” Desjani asked.

“Imagine that you knew what I’d done in past engagements, but still saw me as you once saw Black Jack.”

She thought, eyes hooded, then looked at him. “That guy, Black Jack, would have gone out in a blaze of glory. Again. Seven battleships form the core of the defensive screen. And Black Jack would have five destroyers that were already running low on fuel cells.”

“Yeah. Five destroyers without crews.”

“The programming running the dark ships has to care about losses,” Desjani pointed out, “or those ships would have fought to the end at Atalia rather than taking off. They’ll try to save their battle cruisers even if they’re willing to sacrifice the destroyers.”

He ran one finger through his display, tracing a possible path. “They could do it. A firing run on Ambaru, then bend their vector toward this jump point. All right. I think I know what they think I would do. Let’s get this done.”

Just looking at it from the godlike perspective of the display before his seat, the necessary maneuvers appeared simple. Move this ship here, move that one there, and so on. In practice, changing orbits was pretty complex. Fortunately, it was a complex math problem, and computers were very good at math. All Geary had to do was designate a ship, tell Dauntless ’s maneuvering systems where he wanted that ship to go, and the necessary commands and vectors appeared so quickly that it seemed instantaneous.

He sent the commands to the individual battleships affected, as well as to the commanders of the light cruiser and destroyer divisions that would back up the battleships. Space was huge, so even the many ships he was sending out would form a very sparse screen indeed, but the point wasn’t to build a wall. It was to position mobile units so that they could move to intercept anything trying to get past them.

“What are we going to do?” Desjani asked.

“Hold course for now until we see the dark ships head for Ambaru,” Geary said.

“If we do that, we won’t be in a position to intercept them before they reach Ambaru!”

“I know. Even if we turned now, we couldn’t catch them in time. Every minute they spend heading toward the hypernet gate draws them farther away from a straight shot at Ambaru and allows us to try for an earlier intercept. We’ll wait until less than three hours before the dark ships would likely maneuver. That way they won’t see us changing our vector before their own planned maneuver. If they saw that, the dark ships would probably turn sooner and accelerate faster, and make our intercept impossible. Even if everything works right, it will be close. If the worst happens, I’ve got sixteen heavy cruisers that I can move to stop them after the dark ships clear the battleship screen.”

“Sixteen heavy cruisers?” Desjani shook her head. “Against two battle cruisers like that?” She paused in thought. “Maybe. If they at least make the battle cruisers divert their courses and mess up their firing runs—”

“It will be insurance that we’ll have time to catch those dark ships,” Geary finished.