“The Krell don’t seem to explore much out there. They might have known that old shipyard was going to fall, but getting to it through the rubble belt would have been costly. They seem to have found a few safe pathways to the planet, and they use those almost exclusively.”

“So…,” I said, fascinated. This was all new to me. “Could we use those old defense platforms somehow?”

“We’ve tried,” Cobb said. “But it’s dangerous for us to fly up there as well—the platforms will fire on us too. Also, the Krell are more deadly up in space. Remember the way this planet is shielded? Well, the Krell have strange advanced communications abilities. The planet’s shielding interferes with their capacity to talk to each other; we think that’s why they fly worse down here.

“There’s another issue, smaller,” Cobb said, seeming to grow hesitant about something. “In space, beyond the planet, the Krell can… well, the old crews say that Krell technology lets them read what humans are thinking. And that some people are more susceptible to this than others.”

I shared looks with the rest of the flight. I’d never heard anything like that before.

“Don’t tell anyone I told you that part though,” Cobb said.

“So…,” Arturo said. “This communication interference, and those orbital defenses, are why the Krell don’t bombard us from space?”

“In the early days of Alta,” Cobb said, “they tried to bring in some larger ships, but those got destroyed by orbital defenses. The Krell can only get small, maneuverable ships through to attack us.”

“That doesn’t explain why they send relatively small flights,” Arturo said. “Unless I’m wrong, they’ve never sent an assault larger than a hundred ships. Right?”

Cobb nodded.

“Why not send two hundred? Three hundred?”

“We don’t know. Dig into the classified reports, and you’ll find nothing more than wild theories. Perhaps a hundred ships is the most they can coordinate at once.”

“Okay,” Arturo said, “but why do they seem to only be able to prepare a single lifebuster at a time? Why not load every ship with one, and suicide them into us? Why—”

“What are they?” I interrupted. Arturo had good questions—but in my opinion, less important than that.

Arturo glanced at me, then nodded.

“Do we know, Cobb?” I asked. “In those secret files, does somebody know? Have we ever seen a Krell?”

Cobb changed the hologram to a hovering image of a burned-out helmet and some pieces of armor. I shivered. Krell remains. His hologram was a much more detailed, much more real version of the artistic renditions I’d seen. The photo showed a few scientists standing at a table around the armor, which was squat and bulky. Kind of squarish.

“This is all we’ve ever been able to recover,” Cobb said. “And we only find it in occasional ships we shoot down. One in a hundred or fewer. They aren’t human, of that we’re sure.” He showed another image, a closer-up hologram of one of the helmets, burned out from a crash.