Missile Gap

No indeed, thinks Gregor. It's a miracle Sagan ever passed his political vetting: he's too friendly by far with some of those Russian astronomer guys who are clearly under the thumb of the KGB's First Department. And he's expressed doubts — muted, of course — about the thrust of current foreign policy, which is a serious no-no under the McNamara administration.

"A CAB is a joint committee feeding into the Central Office of Information's external bureaux on behalf of a blue-ribbon panel of experts assembled from the intelligence community," Gregor recites in a bored tone of voice. "Stripped of the bullshit, we're a board of wise men who're meant to rise above narrow bureaucratic lines of engagement and prepare a report for the Office of Technology Assessment to pass on to the Director of Central Intelligence. It's not meant to reflect the agenda of any one department, but to be a Delphi board synergizing our lateralities. Set up after the Cuban fiasco to make sure that we never again get backed into that kind of corner by accidental group-think. One of the rules of the CAB process is that it has to include at least one dissident: unlike the commies we know we're not perfect." Gregor glances pointedly at Fox, who has the good sense to stay silent.

"Oh, I see," Sagan says hesitantly. With more force: "so that's why I'm here? Is that the only reason you've dragged me away from Cornell?"

"Of course not, Doctor," oozes Brundle, casting Gregor a dirty look. The East German defector, Wolff, maintains a smug silence: I are above all this. "We're here to come up with policy recommendations for dealing with the bigger picture. The much bigger picture."

"The Builders," says Fox. "We're here to determine what our options look like if and when they show up, and to make recommendations about the appropriate course of action. Your background in, uh, SETI recommended you."

Sagan looks at him in disbelief. "I'd have thought that was obvious," he says.

"Eh?"

"We won't have any choice," the young professor explains with a wry smile. "Does a termite mound negotiate with a nuclear superpower?"

Brundle leans forward. "That's rather a radical position, isn't it? Surely there'll be some room for maneuver? We know this is an artificial construct, but presumably the builders are still living people. Even if they've got green skin and six eyes."

"Oh. My. God." Sagan leans forward, his face in his hands. After a moment Gregor realizes that he's laughing.

"Excuse me." Gregor glances round. It's the German defector, Wolff, or whatever he's called. "Herr Professor, would you care to explain what you find so funny?"

After a moment Sagan leans back, looks at the ceiling, and sighs. "Imagine a single, a forty-five RPM record with a centre hole punched out. The inner hole is half an astronomical unit — forty-six million miles — in radius. The outer edge is of unknown radius, but probably about two and a half AUs — two hundred and forty five million miles. The disk's thickness is unknown — seismic waves are reflected off a mirror-like rigid layer eight hundred miles down — but we can estimate it at eight thousand miles, if its density averages out at the same as Earth's. Surface gravity is the same as our original planet, and since we've been transplanted here and survived we have learned that it's a remarkably hospitable environment for our kind of life; only on the large scale does it seem different."

The astronomer sits up. "Do any of you gentlemen have any idea just how preposterously powerful whoever built this structure is?"

"How do you mean, preposterously powerful?" asks Brundle, looking more interested than annoyed.

"A colleague of mine, Dan Alderson, did the first analysis. I think you might have done better to pull him in, frankly. Anyway, let me itemise: item number one is escape velocity." Sagan holds up a bony finger. "Gravity on a disk does not diminish in accordance with the inverse square law, the way it does on a spherical object like the planet we came from. We have roughly earthlike gravity, but to escape, or to reach orbit, takes tremendously more speed. Roughly two hundred times more, in fact. Rockets that from Earth could reach the moon just fall out of the sky after running out of fuel. Next item:" another finger. "The area and mass of the disk. If it's double-sided it has a surface area equal to billions and billions of Earths. We're stuck in the middle of an ocean full of alien continents, but we have no guarantee that this hospitable environment is anything other than a tiny oasis in a world of strangeness."