The first wave could be a throwaway, a kamikaze attack to soften us up and evaluate our defenses. Then the second would come in more methodically, and finish the job. Or vice versa: the first group would have twenty minutes to get entrenched; then the second could skip over their heads and hit us hard at one spot-breach the perimeter and overrun the base.

Or maybe they sent out two forces simply because two was a magic number. Or they could launch only eight troop carriers at a time (that would be bad, implying that the carriers were large; in different situations they had used carriers holding as few as 4 troops or as many as 128).

“Three minutes.” I stared at the cluster of monitors that showed various sectors of the mine field. If we were lucky, they’d land out there, out of caution. Or maybe pass over it low enough to detonate mines.

I was feeling vaguely guilty. I was safe in my hole, doodling, ready to start calling out orders. How did those seventy sacrificial lambs feel about their absentee commander?

Then I remembered how I had felt about Captain Stott that first mission, when he’d elected to stay safely in orbit while we fought on the ground. The rush of remembered hate was so strong I had to bite back nausea.

“Hilleboe, can you handle the lasers by yourself?”

“I don’t see why not, sir.”

I tossed down the pen and stood up. “Charlie, you take over the unit coordination; you can do it as well as I could. I’m going topside.”

“I wouldn’t advise that, sir.”

“Hell no, William. Don’t be an idiot.”

“I’m not taking orders, I’m giv—”

“You wouldn’t last ten seconds up there,” Charlie said.

“I’ll take the same chance as everybody else.”

“Don’t you hear what I’m saying. They’ll kill you!”

“The troops? Nonsense. I know they don’t like me especially, but—”

“You haven’t listened in on the squad frequencies?” No, they didn’t speak my brand of English when they talked among themselves. “They think you put them out on the line for punishment, for cowardice. After you’d told them anyone was free to go into the dome.”

“Didn’t you, sir?” Hilleboe said.

“To punish them? No, of course not.” Not consciously. “They were just up there when I needed … Hasn’t Lieutenant Brill said anything — to them?”

“Not that I’ve heard,” Charlie said. “Maybe she’s been too busy to tune in.”

Or she agreed with them. “I’d better get—”

“There!” Hilleboe shouted. The first enemy ship was visible in one of the mine field monitors; the others appeared in the next second. They came in from random directions and weren’t evenly distributed around the base. Five in the northeast quadrant and only one in the southwest. I relayed the information to Brill.

But we had predicted their logic pretty well; all of them were coming down in the ring of mines. One came close enough to one of the tachyon devices to set it off. The blast caught the rear end of the oddly streamlined craft, causing it to make a complete flip and crash nose-first. Side ports opened up and Taurans came crawling out. Twelve of them; probably four left inside. If all the others had sixteen as well, there were only slightly more of them than of us. In the first wave.

The other seven had landed without incident, and yes, there were sixteen each. Brill shuffled a couple of squads to conform to the enemy’s troop concentration, and she waited.

They moved fast across the mine field, striding in unison like bowlegged, top-heavy robots, not even breaking stride when one of them was blown to bits by a mine, which happened eleven times.

When they came over the horizon, the reason for their apparently random distribution was obvious: they had analyzed beforehand which approaches would give them the most natural cover, from the rubble that the drones had kicked up. They would be able to get within a couple of kilometers of the base before we got any clear line of-sight of them. And their suits had augmentation circuits similar to ours, so they could cover a kilometer in less than a minute.

Brill had her troops open fire immediately, probably more for morale than out of any hope of actually hitting the enemy. They probably were getting a few, though it was hard to tell. At least the tachyon rockets did an impressive job of turning boulders into gravel.

The Taurans returned fire with some weapon similar to the tachyon rocket, maybe exactly the same. They rarely found a mark, though; our people were at and below ground level, and if the rocket didn’t hit something, it would keep going on forever, amen. They did score a hit on one of the gigawatt lasers, though, and the concussion that filtered down to us was strong enough to make me wish we had burrowed a little deeper than twenty meters.

The gigawatts weren’t doing us any good. The Taurans must have figured out the lines of sight ahead of time, and gave them wide berth. That turned out to be fortunate, because it caused Charlie to let his attention wander from the laser monitors for a moment.

“What the hell?”

“What’s that, Charlie?” I didn’t take my eyes off the monitors. Waiting for something to happen.

“The ship, the cruiser — it’s gone.” I looked at the holograph display. He was right; the only red lights were those that stood for the troop carriers.

“Where did it go?” I asked inanely.

“Let’s play it back.” He programmed the display to go back a couple of minutes and cranked out the scale to where both planet and collapsar showed on the cube. The cruiser showed up, and with it, three green dots. Our “coward,” attacking the cruiser with only two drones.

But he had a little help from the laws of physics.

Instead of going into collapsar insertion, he had skimmed around the collapsar field in a slingshot orbit. He had come out going nine-tenths of the speed of light; the drones were going .99c, headed straight for the enemy cruiser. Our planet was about a thousand light-seconds from the collapsar, so the Tauran ship had only ten seconds to detect and stop both drones. And at that speed, it didn’t matter whether you’d been hit by a nova-bomb or a spitball.

The first drone disintegrated the cruiser, and the other one, .01 second behind, glided on down to impact on the planet. The fighter missed the planet by a couple of hundred kilometers and hurtled on into space, decelerating with the maximum twenty-five gees. He’d be back in a couple of months.

But the Taurans weren’t going to wait. They were getting close enough to our lines for both sides to start using lasers, but they were also within easy grenade range. A good-size rock could shield them from laser fire, but the grenades and rockets were slaughtering them.

At first, Brill’s troops had the overwhelming advantage; fighting from ditches, they could only be harmed by an occasional lucky shot or an extremely well-aimed grenade (which the Taurans threw by hand, with a range of several hundred meters). Brill had lost four, but it looked as if the Tauran force was down to less than half its original size.

Eventually, the landscape had been torn up enough so that the bulk of the Tauran force was able to fight from holes in the ground. The fighting slowed down to individual laser duels, punctuated occasionally by heavier weapons. But it wasn’t smart to use up a tachyon rocket against a single Tauran, not with another force of unknown size only a few minutes away.

Something had been bothering me about that holographic replay. Now, with the battle’s lull, I knew what it was.

When that second drone crashed at near-lightspeed, how much damage had it done to the planet? I stepped over to the computer and punched it up; found out how much energy had been released in the collision, and then compared it with geological information in the computer’s memory.

Twenty times as much energy as the most powerful earthquake ever recorded. On a planet three-quarters the size of Earth.