She sat down next to Dale, who had been paying closer attention. “What is he talking about?”

“A weapon to use against the Reivers.”

“Oh, really?”

“If you have a life form that is pure information, the weapon to use is—”

“A lie?” Makali said.

“Well, corrupt information. Or corrupt information that keeps on corrupting.”

“What does that mean in practical terms?”

“Damned if I know,” Dale said. “But I think we’re into biological warfare. Bug on bug, something that will turn their strengths against them.”

She let her head loll back. Among the many drawbacks of living on adrenaline for forty hours straight was the need to sit down and effectively shut down more often and more completely. She felt that now…a bone-deep weariness that made her question every decision, every hope.

Nothing looked good right now. “I was just thinking,” she said to Dale, on the chance that stirring herself for a new conversation would restart her motor. “Why were the Skyphoi in the dead habitat to begin with?”

“What do you mean?”

“Were they there to help Dash, or catch him?”

“I assume it was to help him…they were vectored there by whatever voices they hear.”

“But what if they were trying to catch Dash instead? Or even kill him?”

“Well, okay, but they haven’t said anything—”

“They can’t say shit that we understand! Maybe all those freaky colors have been the Skyphoi saying, ‘The Sentry is a murderer!’”

She suddenly turned to look at Dash again.

There was an item on the Sentry’s left lower arm. That was what she had been recording without actually seeing.

It looked like a piece of fabric.

“You’ve seen how difficult it is to communicate from one habitat to another, or from one race to another! And their Revenant or communicator is dead.”

“I think you’ve gone without food or sleep for too long.”

She nudged Dale. “Okay, check out the Sentry’s arm. Any idea what that is?”

Dale stiffened. “It’s from Valya’s bag,” he said.

“Ask yourself what he’s doing with it.”

“I don’t have to,” he said. “The Skyphoi didn’t kill Valya—fucking Dash did!”

Dale was already in motion. Makali put her hand on his arm. “What do you think you’re doing?”

“Good question.” That was Zack Stewart from across the railcar. He had handed the Tik-Talk off to Zhao and had been watching Makali and Dale.

Makali saw no way to tell Zack of their suspicions without alerting Dash, who remained busy and apparently oblivious four meters away.

Not secretly, of course. But who needed secrets? “We were just talking some Earth history.”

Zack knew that wasn’t true, that they were hiding something. “Okay…”

“About Americans’ involvement in various conflicts going back a century…and how we frequently discovered we had been slow to recognize the threat of fascism.”

“Yeah,” Zack said. Rachel and Pav were looking at each other. Yvonne was staring straight at Makali.

“Like Hitler,” Dale said. “Americans were slow to realize what a danger Hitler was—” And here Dale glanced toward Dash.

Moving with a speed Makali found surprising and alarming, the Sentry pushed itself away from the wall, pulled itself toward the open side of the railcar, and jumped out.

Rachel screamed. The dog barked and jumped out, too.

“What’s going on?” Yvonne said. She pointed to the Architect, who was otherwise impassive. “He’s very confused.”

“Dash is working for the other side,” Dale said. “It killed Valya and the Skyphoi Revenant—”

The railcar rattled to a violent stop, throwing everyone forward.

“Now what?” Dale said. “Another blackout?”

“He stopped us,” Yvonne said.

“Well, make him start us again,” Zhao said. “We can’t waste more time.”

“What about Cowboy?” Rachel said.

“We’re not stopping for a dog,” Zack said. “But we’re stopped, right?” Yvonne nodded.

“Let’s find the son of a bitch before he does something else to us.”

He headed for the hatch and jumped into the dark tunnel.

Rachel Stewart started to follow her father out of the railcar, but Makali got in her way. “You stay.” She turned to Pav. “Keep her here.”

Pav grabbed for Rachel’s arm.

Now Zhao was up. “What are you going to do?”

“I’m going to kill that thing,” Dale said, “even if I have to use bare hands.”

“Unlikely,” Zhao said.

“First we’re going to catch him and make him talk,” Makali said. “Yvonne, if you think your link with the Architect will work at a distance, you should come with us.”

The astronaut headed for the open hatch. The Architect didn’t move.

Zack was already fifteen meters ahead of them, running after Dash. But the Destiny commander’s feet were obviously hindering him; Makali saw him slow, hop in pain, then try to get going again.

She and Dale quickly caught up with him. Yvonne was close behind. “Hey, Dash!” Dale shouted.

The Sentry ignored him. But the alien couldn’t ignore Cowboy. The dog was the fastest being in the tunnel—with a snarling yelp, he caught the Sentry and began tugging at its garments.

The Sentry actually stopped. As it struggled with the dog, it faced the approaching humans. Now what? Makali wondered. She well remembered the story of Pogo Downey’s ill-fated encounter with a hostile Sentry.

But she didn’t need a plan of action after all; Dale simply rushed the Sentry like a football linebacker, slamming the alien between knees and waist.

The Sentry was staggered, but not felled—until Zack Stewart hit him, too. Dash hit the wall, then stumbled sideways.

With the dog barking and looking for an opening, Dale and Zack, working together for the first time, tried to pin the Sentry.

It’s come to this, Makali realized. Two weeks ago she could only fantasize about discovering hard evidence of alien life in the universe. Now she was tackling a genuine alien being. If it weren’t so tragic, it would be hilarious.

“We saved you,” Zack yelled at Dash.

“I…expressed gratitude.” It was strange hearing a calm, monotonic voice emerge from the translation unit when the Sentry was clearly struggling.

“Didn’t last long.”

“I had my mission.”

“I don’t understand your mission. Or anything you’ve done.”

“We are bred to fight, even our own kind. It’s in our water—”

Before Yvonne or Makali could add their weight, Dash flung them aside as if they were angry cats. Dale landed on Cowboy, who squealed in pain.

With impressive speed and determination, Dash was off again, soon with four humans and a dog in ragged pursuit.

Within moments Dash had passed through a T-junction in the tunnel. As Makali, Zack, Dale, and Yvonne huffed and puffed in the Sentry’s wake, Zack said, “We’re never going to catch him again.”

“Maybe we should let him go,” Makali said, mindful of Zhao’s urging about their mission to the power core.

“No. He’s killed humans and he’s involved with the Reivers. We need what he knows.”

“No we don’t,” Yvonne said. “We need to…”

She turned back and looked at the railcar a hundred meters away.

It was moving toward them.

“We need to get out of the way,” she said. “This way!” She pushed or dragged the other three into the side tunnel. Cowboy was faster than all of them.

They had barely exited the main passage before the railcar flashed past them like a whisper. Makali felt the explosion of displaced air and a disturbing rippling sensation, as if her entire body had been stretched wide, then allowed to snap back to its original state.

“What the hell was that?” Dale said.

“Cat’s-eye passing,” Yvonne said, as if that explained anything.

The railcar had stopped a few meters away. Zhao, Pav, and Rachel were emerging slowly, like accident victims. “Who did that?” Zhao said.

“Keanu did it,” Yvonne said simply.