David Weber - Old Soldiers

She/they considered the timing. If she/they continued on her/their current heading at current speed, the flanking column would be past any point at which she/they could subsequently intercept it short of Fourth Battalion's position in another twelve minutes. And, if that column got past her/them, worst-case, Fourth Battalion would find itself ground into the mud under the tracks of a full battalion of heavy armored vehicles. Best case, she/they would find themselves trapped in a constricted, mountainous valley between both Dog Boy armored battalions while the Enemy ignored the Fourth to concentrate on killing her/them.

Pity. She/they had rather hoped the Puppies' CO would decide to send all of his mechs around her/their flank. Unfortunately, he'd turned out to be too wary for that.

"Now it begins to retreat!" Ka-Frahkan flapped his ears in frustration. "Nameless Ones! What sort of game is this damned machine playing?!"

The Bolo icon on his display had, indeed, begun to retreat—and at a far higher rate of speed, at that.

But it was too late. Major Julhar Ha-Shan's Second Armored Battalion and Major Thuran Ha-Nashum's Third Infantry were already past it. The Bolo was faster than Ha-Shan's heavies, but it also had much further to go if it wanted to retreat to its militia blocking position before Ha-Shan and Ha-Nashum reached it, and there was no way even a Bolo could catch them now without using the pod in which it But why had it waited so long?

Of course, Na-Lythan's First Armored Battalion and the rest of Colonel Ka-Somal's infantry were also advancing once more, along the route Ka-Frahkan had designated Axis Three, if much more slowly and cautiously than Ha-Shan's battalion. They would have entered the Bolo's engagement range, had it continued to advance on its original course, within another thirty minutes or so. The fight when they reached that point would have been ugly, and Ka-Frahkan was far from certain of what its final outcome would have been, given how the Human machine's individual power and superior technology would have offset his own forces' advantages in tonnage, numbers, and combined firepower. He'd been willing to court the engagement anyway, however, if it would have pinned the Bolo in place while Second Armored got on with the business of destroying the blocking position and advanced upon the colony itself. That was why he'd held First Armored back and sent Ha-Shan ahead. Sa-Thor's heavies were marginally better suited to a direct engagement against the Bolo, and Ha-Shan's additional missile power would make his battalion far more dangerous to the Human settlement once he got past the blocking militia.

But now the accursed Bolo seemed unwilling to give him that engagement ... even though it was self-evidently too late for it to reverse course and intercept Second Armored!

Theslask Ka-Frahkhan glared at his tactical plot and tried not to grind his teeth together as he tried to deduce just what hellish surprise the Bolo and its Human commander were attempting to spring upon him.

Maneka/Lazarus monitored the flanking column's position carefully. It was continuing to advance, and she/they were tempted to continue her/their advance and engage the remainder of the Melconian force head on. Unfortunately, if she/they did, the main Puppy column would engage her/them well before the flanking column reached the decisive point. It was as certain as anything could be that she/they would have taken damage in that engagement, and she/they could not afford to risk that. Not yet. The flanking column had to be dealt with before she/they could accept any reduction in her/their own capabilities.

"Timing," her/their human half thought. "It's all a matter of timing, now."

"It always is," her/their Bolo half replied.

Captain Farka Na-Rohrn felt his spirits rising as Second Armored Battalion thundered eastward behind his Heimdall. He could see the Human Bolo on his tactical display, although there were enough mountains between them to prevent it from seeing him, praise the Nameless Lord! And while Na-Rohrn had never claimed to be a tactical genius, it seemed obvious to him that the Bolo had made a fatal error.

The positions and maximum possible rates of advance indicated on his display made it abundantly clear that there was, quite simply, no possible way for the Bolo to intercept Major Ha-Shan's armor and Major Ha-Nashum's infantry before they wiped out the Human militia positioned to stop them. And after that, there would be nothing between them and the Human colony.

There were only six of them, and she/they had added the rather special warheads they mounted to her/their normal ammunition mix in place of the same number of more conventional warheads over three weeks ago. Now the missiles carrying those warheads erupted from the heavily armored wells of her/their vertical-launch missile system and rose on pillars of flame until they were high enough for their counter-gravity drives to take over. Then the thundering wakes of fire vanished, and the missiles screamed suddenly southeastward at seven times the speed of sound.

"General Ka-Frahkan!" a sensor tech said sharply. "The Bolo has just launched missiles!"

"At us?" Ka-Frahkan demanded, spinning around to face the master tactical plot.

"No, sir," the noncom replied in puzzled tones. "At Colonel Ha-Shan."

"Incoming!" Ha-Shan's sensor operator announced suddenly. "Multiple—six incoming from the Bolo, sir! Mach seven!"

Ha-Shan's eyes instantly found the missile icons on his own display. Even at that velocity, there was plenty of time, he thought as the targeting systems of his armored units' antimissile defenses turned onto the threat bearing. Besides, that was a ridiculously low number of missiles for a target like his. His command Surtur alone could have defeated all of them with ease, Human technology or no. So what was the damned Bolo up to now?

"Impact projection," the sensor operator said, and Ha-Shan blinked.

That couldn't be right! He looked at the visual display showing the terrain directly to his west. The river-cut valley through which his battalion was currently passing had, indeed, grown narrower, with precipicelike cliffs looming on both sides. The ones to the west were both higher and steeper than the ones to the east, and if the missiles' impact point was properly projected, all six of them were going to land harmlessly on the other side of the mountain which reared that protective rampart. Which was stupid. Yet one thing no Bolo had ever been accused of was stupidity, so what—?

The same mountains which protected the Melconian column from Maneka/Lazarus' direct fire also protected her/their missiles from interception. They sped directly to their targets, separating, spreading out, adjusting their trajectories with finicky precision.

At precisely the correct moment, all six of them killed their drives and continued onward at just over seven thousand kilometers per hour. They slammed into the mountainside, and the superdense, ballistically shaped deep-penetrator warheads she/they had mounted upon them drilled through solid earth and stone like hypervelocity bullets. They plunged deep into the heart of the mountain, driving directly into the fault pattern Maneka/Lazarus' deep scan radar mapping had revealed weeks before.

And then six megaton-range warheads detonated as one.

The stupendous shockwave was enough to shake even a Surtur like a toy. Ha-Shan had never experienced an earthquake before, and he was ill-prepared to feel his 18,000-ton mech shivering like a frightened child. But Surturs were designed and engineered to survive far worse than a little shaking, and he felt his speeding pulse began to slow once more.