"Simulation processes."

"Yeah, simulation processes, inside some sort of super super-computer. But if that’s true, then whoever is behind this should be able to spy on us better than any Big Brother ever could in the real world. We should’ve been caught and rebooted the minute we began to get suspicious."

Both Ellens started to answer. They stopped, then interrupted each other again.

"Back to who’s-got-the-token," one said, holding up the dollar coin. "Dixie Mae, that is a mystery, but not as big as it seems. If Reich is using the sort of upload and simulation techniques I know about, then what goes on inside our minds can’t be interpreted directly.

Thoughts are just too idiosyncratic, too scattered. If we are simulations in a large quantum computer, even environment probes would be hard to run."

"You mean things like spy cameras?"

"Yes. They would be hard to implement, since in fact they would be snooping on the state of our internal imagery. All this is complicated by the fact that we’re probably running thousands of times faster than real time. There are maybe three ways that Gerry could snoop: he could just watch team output, and if it falls off, he’d know that something had gone wrong–and he might reboot on general principles."

Suddenly Dixie Mae was very glad that they hadn’t taken more volunteers on this hike.

"The second snoop method is just to look at things we write or the output of software we explicitly run. I’ll bet that anything that we perceive as linear text is capable of outside interpretation." She looked at Victor. "That’s why no note-taking." Dixie Mae still had his notepad.

"It’s kinda stupid," said Victor. "First it was no pictures and now not even notes.

"Hey, look!" said the Ellens. "B0917!" But it wasn’t a building, just a small sign wedged among the rocks.

They scrambled off the asphalt onto a dirt path that led directly up the hillside.

Now they were so near the hill crest that the horizon was just a few yards away. Dixie Mae couldn’t see any land beyond. She remembered a movie where poor slobs like themselves got to the edge of the simulation ... and found the wall at the end of their universe. But they took a few more steps and she could see over the top. There was a vista of further, lower hills, dropping down into the San Fernando Valley. Not quite hidden in the haze she could see the familiar snakey line of Highway 101. Tarzana.

Ellen and Ellen and Victor were not taking in the view. They were staring at the sign at the side of the path. Fifteen feet beyond that was a construction dig. There were building supplies piled neatly along the edge of the cut, and a robo-Cat parked on the far side. It might have been the beginning of the construction of a standard-model LotsaTech building ... except that in the far side of the pit, almost hidden in shadows, there was a circular metal plug, like a bank vault door in some old movie.

"I have this theory," said the token holder. "If we get through that door, we may find out what your email is all about."

"Yup." The twins bounced down a steeply cut treadway into the pit. Dixie Mae and Victor scrambled after them, Victor clumsily bumping into her on the way down. The bottom of the pit was like nothing before. There were no windows, no card swipe. And up close, Dixie Mae could see that the vault door was pitted and scratched.

"They’re mixing metaphors," said the token holder. "This entrance looks older than the pit."

"It looks old as the hills," Dixie Mae said, running her hand over the uneven metal–and half expecting to feel weirdo runes. "Somebody is trying to give us clues ... or somebody is a big sadist. So what do we do? Knock a magic knock?"

"Why not?" The two Ellens took her tattered email and laid it out flat on the metal of the door.

They studied the mail headers for a minute, mumbling to each other. The token holder tapped on the metal, then pushed.

"Together," they said, and tapped out a random something, but perfectly in synch.

That had all the effect you’d expect of tapping your fingers on ten tons of dead steel.

The token holder handed the email back to Dixie Mae. "You try something."

But what? Dixie Mae stepped to the door. She stood there, feeling clueless. Off to the side, almost hidden by the curve of the metal plug, Victor had turned away.

He had the notepad.

"Hey!" She slammed him into the side of the pit. Victor pushed her away, but by then the Ellens were on him. There was a mad scramble as the twins tried to do all the same things to Victor.

Maybe that confused him. Anyway, it gave Dixie Mae a chance to come back and punch him in the face.

"I got it!" One of the twins jumped back from the fighting. She had the notepad in her hands.

They stepped away from Victor. He wasn’t going to get his notepad back. "So, Ellen," said Dixie Mae, not taking her eyes off the sprawled figure, "what was that third method for snooping on us?"

"I think you’ve already guessed. Gerry could fool some idiot into uploading as a spy." She was looking over her twin’s shoulder at the notepad screen.

Victor picked himself up. For a moment he looked sullen, and then the old superior smile percolated across his features. "You’re crazy. I just want to break this story back in the real world. Don’t you think that if Reich were using spies, he’d just upload himself?"

"That depends."

The one holding the notepad read aloud: "You just typed in: ‘925 999 994 know. reboot’. That doesn’t sound like journalism to me, Victor."

"Hey, I was being dramatic." He thought for a second, and then laughed. "It doesn’t matter anymore! I got the warning out. You won’t remember any of this after you’re rebooted."

Dixie Mae stepped toward him. "And you won’t remember that I broke your neck."

Victor tried to look suave and jump backwards at the same time. "In fact, I will remember, Dixie Mae. See, once you’re gone, I’ll be merged back into my body in Doc Reich’s lab."

"And we’ll be dead again!"

Ellen held up the notepad. "Maybe not as soon as Victor thinks. I notice he never got past the first line of his message; he never pressed return. Now, depending on how faithfully this old notepad’s hardware is being emulated, his treason is still trapped in a local cache–and Reich is still clueless about us."

For a moment, Victor looked worried. Then he shrugged. "So you get to live the rest of this run, maybe corrupt some other projects–ones a lot more important than you. On the other hand, I did learn about the email. When I get back and tell Doc Reich, he’ll know what to do. You won’t be going rogue in the future."

Everyone was silent for a second. The wind whistled across the yellow-blue sky above the pit.

And then the twins gave Victor the sort of smile he had bestowed on them so often. The token holder said, "I think your mouth is smarter than you are, Victor. You asked the right question a second ago: Why doesn’t Gerry Reich upload himself to be the spy? Why does he have to use you?"

"Well," Victor frowned. "Hey, Doc Reich is an important man. He doesn’t have time to waste with security work like this."

"Really, Victor? He can’t spare even a copy of himself?"

Dixie Mae got the point. She closed in on Victor. "So how many times have you been merged back into your original?"

"This is my first time here!" Everybody but Victor laughed, and he rushed on, "But I’ve seen the merge done!"

"Then why won’t Reich do it for us?"

"Merging is too expensive to waste on work threads like you," but now Victor was not even convincing himself.

The Ellens laughed again. "Are you really a UCLA journalism grad, Victor? I thought they were smarter than this. So Gerry showed you a re-merge, did he? I bet that what you actually saw was a lot of equipment and someone going through very dramatic convulsions. And then the ‘subject’ told you a nice story about all the things he’d seen in our little upload world. And all the time they were laughing at you behind their hands. See, Reich’s upload theory depends on having a completely regular target. I know that theory: the merge problem–loading onto an existing mind–is exponential in the neuron count. There’s no way back, Victor."