"But what is it?"

"Thermite is aluminum and iron oxide," David said. "It burns very hot-three thousand degrees-and so bright you can't look directly at it. And it'll melt steel for welding."

"How much of that have we got?" I said to Rosie. "Because we can use it tonight."

"There's four boxes back there." She plucked one tube from the box. "So how do you set 'em off?"

"Be careful, Rosie. That's a magnesium wrapper. Any decent heat source will ignite it."

"Even matches?"

"If you want to lose your hand. Better use road flares, something with a fuse."

"I'll see," she said, and she disappeared around the corner.

The radiation counter was still clicking. I turned to the sink. Mae had capped the isotope tube. She was now pouring the straw-colored liquid into a Windex bottle. "Hey, guys?" It was Bobby Lembeck again. "I'm picking up some instability. Wind's fluctuating at twelve knots."

"Okay," I said. "We don't need to hear every little change, Bobby."

"I'm seeing some instability, is all."

"I think we're okay for the moment, Bobby."

Mae was going to be another few minutes, in any case. I went over to a computer workstation and turned it on. The screen glowed; there was a menu of options. Aloud, I said, "Ricky, can I put up the swarm code on this monitor?"

"The code?" Ricky said. He sounded alarmed. "What do you want the code for?"

"I want to see what you guys have done."

"Why?"

"Ricky, for Christ's sake, can I see it or not?"

"Sure, of course you can. All the code revisions are in the directory slash code. It's passworded."

I was typing. I found the directory. But I wasn't being allowed to enter it. "And the password is?"

"It's l-a-n-g-t-o-n, all lowercase."

"Okay."

I entered the password. I was now in the directory, looking at a list of program modifications, each with file size and date. The document sizes were large, which meant that these were all programs for other aspects of the swarm mechanism. Because the code for the particles themselves would be small-just a few lines, maybe eight, ten kilobytes, no more. "Ricky."

"Yes, Jack."

"Where's the particle code?"

"Isn't it there?"

"God damn it, Ricky. Stop screwing around."

"Hey, Jack, I'm not responsible for the archiving-"

"Ricky, these are workfiles, not archives," I said. "Tell me where."

A brief pause. "There should be a subdirectory slash C-D-N. It's kept there."

I scrolled down. "I see it."

Within this directory, I found a list of files, all very small. The modification dates started about six weeks ago. There was nothing new from the last two weeks. "Ricky. You haven't changed the code for two weeks?"

"Yeah, about that."

I clicked on the most recent document. "You got high-level summaries?" When these guys had worked for me, I always insisted that they write natural language summaries of the program structure. It was faster to review than documentation within the code itself. And they often solved logic problems when they had to write it out briefly. "Should be there," Ricky said.

On the screen, I saw: /.Initialize./

For j=1 to L x V do

Sj = 0 /.set initial demand to 0/

End For

For i=l to z do

For j = 1 to L x V do ij = (state (x,y,z)) /.agent threshold param./ Ш ij = (intent (Cj,Hj)) /.agent intention fill./ Response = 0 /. begin agent response./ Zone = z(i) /. intitial zone unlearned by agent./ Sweep =1 /. activate agent travel./ End For End For /.Main./ For kl=1 to RVd do For tm=1 to nv do For = i to j do /. tracking surrounds./ Ш ij = (intent (Cj,Hj)) /.agent intention fill./ ij «» (state (x,y,z)) /.agent is in motion./ ikl = (filed (x,y,z)) /.track nearest agents./ I scanned it for a while, looking for how they had changed it. Then I scrolled down into the actual code, to see the implementation. But the important code wasn't there. The entire set of particle behaviors was marked as an object call to a something titled "compstat-do."

"Ricky," I said, "what's 'compstat-do'? Where is it?"

"Should be there."

"It's not."

"I don't know. Maybe it's compiled."

"Well that isn't going to do me any good, is it?" You couldn't read compiled code. "Ricky, I want to see that damn module. What is the problem?"

"No problem. I have to look for it, is all."

"Okay…"

"I'll do it when you get back."

I glanced over at Mae. "Have you gone through the code?"

She shook her head. Her expression seemed to say it was never going to happen, that Ricky would make up more excuses and keep putting me off. I didn't understand why. I was there to advise them on the code, after all. That was my area of expertise. In the next room, Rosie and David were poking through the shelves of supplies, looking for radio relays. They weren't having any success. Across the room, Charley Davenport farted loudly and cried, "Bingo!"

"Jesus, Charley," Rosie said.

"You shouldn't hold things in," Charley said. "It makes you sick."

"You make me sick." Rosie said.

"Oh, sorry." Charley held up his hand, showing a shiny metal contraption. "Then I guess you don't want this remote-controlled compression valve."

"What?" Rosie said, turning.

"Are you kidding?" David said, going over to look.

"And it's got a pressure rating of ADC twenty pi."

"That should work fine," David said.

"If you don't fuck it up," Charley said.

They took the valve and went to the sink, where Mae was still pouring, wearing her heavy gloves. She said, "Let me finish…"

"Will I glow in the dark?" Charley said, grinning at her.

"Just your farts," Rosie said.

"Hey, they already do that. 'Specially when you light 'em."

"Jesus, Charley."

"Farts are methane, you know. Burns with a hard blue gemlike flame." And he laughed.

"I'm glad you appreciate yourself," Rosie said. "Because nobody else does."

"Ouch, ouch," Charley said, clutching his breast. "I die, I die…"

"Don't get our hopes up."

My headset crackled. "Hey guys?" It was Bobby Lembeck again. "Wind's just dropped to six knots."

I said, "Okay." I turned to the others. "Let's finish up, guys."

David said, "We're waiting for Mae. Then we'll fit this valve."

"Let's fit it back in the lab," I said.

"Well, I just want to make sure-"

"Back at the lab," I said. "Pack it up, guys."

I went to the window and looked out. The wind was still ruffling the juniper bushes, but there was no longer a layer of sand blowing across the ground.

Ricky came on the headset: "Jack, get your fucking team out of there."

"We're doing it now," I said.

David Brooks said in a formal tone, "Guys, there's no point in leaving until we have a valve that we know fits this bottle-"

"I think we better go," Mae said. "Finished or not."

"What good would that do?" David said.

"Pack up," I said. "Stop talking and pack it up now."

Over the headset, Bobby said, "Four knots and falling. Fast."

"Let's go, everybody," I said. I was herding them toward the door.

Then Ricky came on. "No."

"What?"

"You can't leave now."

"Why not?"

"Because it's too late. They're here."