Ziegler consulted her notes, refreshing herself on the briefing she’d had on this topic. "We call that region ‘the Kuiper belt.’ " She looked at the jurors.

"The jury may have heard of the asteroid belt between Mars and Jupiter, but that is a different phenomenon; the Kuiper belt is much farther out, past the orbit of Neptune." She turned back to Rendo. "Our theories of planetary formation suggest that any star with planets is likely to have such a region surrounding it."

"And we have learned from that insight," said Rendo. "Dr. Calhoun explained short-period comets to me, which, I understand are debris from the Kuiper belt that has fallen in toward the inner solar system. I suspect such comets are spectacular to behold, but my world has never seen one, at least not in all of Tosok recorded history." Rendo paused, as if considering how best to make his point. "Alpha Centauri is a triple star system, Ms. Ziegler. Each of these three stars has a gravitational effect on matter orbiting beyond a certain distance from the others. From what I learned from Dr. Calhoun, I would say it was likely that Alpha Centauri A, B, and C did indeed have Kuiper belts left over after they coalesced out of primordial dust and gas, just as such a belt was left over after your sun did the same. But the gravitational dance of A and B long ago cleared out each other’s Kuiper belts. Without the clue of having seen short-period comets in our own sky, it never occurred to us that a disk of debris would ever have existed close in to our own sun, let alone around other suns. The accident did indeed occur as I described, we do indeed need human assistance, and as I told Mr. Rice, none of my people would have jeopardized that assistance by committing murder."

Ziegler realized she wasn’t helping her cause. "No further questions," she said.

Something about the courtroom discussion of the orbital dynamics of the Alpha Centauri system was bothering Frank Nobilio, but he wasn’t exactly sure what. Of course, Frank wasn’t an astronomer himself (his doctorate was in the history of science), but he’d taken one undergrad astronomy course. Still, there was something that didn’t quite add up. In the past, when he’d had an astronomical question, Frank had simply put it to Cletus Calhoun, but now that wasn’t possible.

Or was it?

Frank drove out to KCET, the Los Angeles PBS affiliate. The people there were only too happy to give him access to a viewing room, with a thirty-one-inch TV and a stereo VCR. Frank’s memory was right: there had been an episode on this very topic. He sat in the dark, sipping Diet Pepsi from a can.

The screen filled with a corporate logo. "This program," said a female voice, "is made possible by a grant from the Johnson Johnson Family of Companies, and by annual financial support from viewers like you."

The camera started tight on a campfire, then pulled back to show that it was surrounded by primitive, beetle-browed humans. Sparks rose from the fire, and the camera titled up, following them as they continued up toward the moonless night sky. The sparks soon disappeared, but the sky was filled with stars, the Milky Way arching overhead. The camera kept tilting up, and the pounding rhythm of Jerry Lee Lewis’s piano started in the background. Soon the camera was zooming into space, then the image flipped around to show Earth’s nightside and, rising over its curving edge, the sun. The camera moved in toward the sun, its spotted face filling the screen, a prominence arching up from the surface. Lewis’s voice belted out the words "Goodness gracious! Great balls of fire!" The prominence fell back toward the surface of the sun, but the series title was left in flaming letters glowing in space: GREAT BALLS OF FIRE!

The camera moved through space as the song continued, past a bloated red giant star adjacent to a black hole, which was pulling material from it; past a binary star system; past a pulsar flashing on and off; through the Pleiades, their blue light diffused by the nebulosity surrounding them…

A second title appeared: WITH CLETUS CALHOUN. Jerry Lee Lewis sang the words "Great Balls of Fire!" once more, and the credit sequence ended.

After a brief fade to black, the image of Clete himself came up, all gangly limbs and goofy smile. It was twilight, and he was standing on a boardwalk at the edge of a subtropical swamp.

A third title appeared: PROGRAM 3: JUST OVER YONDER.

"Evening, y’all," said Clete, smiling. Frank felt his eyes stinging. God, how he missed that man. In the darkened room, it was almost like he was really there with him.

"Y’all know I come from the South," continued Clete, looking straight into the camera — straight at Frank. "From Tennessee, t’be ’zact. But tonight we’ve up and gone even farther south than that — just ’bout as far south as a body can go and still be in the good ol’ U.S. of A. We’re here in Everglades National Park, right down near the tip o’ Florida." In the background, an egret flew against the pink sky, its long legs and neck not unlike those of Calhoun himself. "We’ve come on down here to see something y’all can’t see farther north." He pointed with a skinny arm and the camera followed until it had centered its view on a bright star, just above the horizon, framed between two bulrushes.

"That there’s Alpha Centauri," said Clete. "Don’t look like nothin’ special, but it’s the closest star to the Earth, ’cepting the Sun. It’s ’round bout twenty-five trillion miles away — just over yonder. Our nearest neighbor in space."

Frank hit the fast-forward button. Clete zipped around silently, like a Keystone Kop. He was intercut with graphics showing the constellation of the Centaur. After a time Frank released the button.

" — but Alpha Centauri ain’t just one star," said Clete. "It’s actually three of ’em, all very close together. We call ’em — Alpha Centauri A, Alpha Centauri B, and — wait for it — Alpha Centauri C. Us astronomers — we got the souls of poets." His broad face split in a grin. "Actually, Alpha Centauri C is the closest of the bunch to us, so sometimes we do call it by a fancier name: Proxima Centauri — Proxima like in ‘proximity.’ Nuther thing y’all should know about astronomers: we like fifty-dollar words, ’cuz that’s as close as most of us ever gets to a fifty-dollar bill." He grinned again.

The image changed to Mardi Gras in New Orleans, with Clete walking down a street at night. He paused to watch a man in gaudy dress juggling three flaming torches. " ‘Course," said Clete, "when you got three stars close together, things get very interesting indeed." The camera zoomed in on the dancing torches, then pulled out of the fireplace inside Clete’s mountain cabin — a common sight in the series. He was sitting behind an old wooden desk. A potbelly stove was in the background, and a hunting rifle hung on the wooden wall behind him. A bowl of fruit sat on the desktop.

"A and B are big stars," Clete said. He picked a grapefruit out of the fruit bowl. "This here could be A — a big yellow star, very much like our own sun.

’Fact, A’s a tetch bigger than our sun, and about fifty percent brighter."

He reached into the fruit bowl and pulled out an orange. "Now this here, this could be B — a smaller, dimmer, orange star. B’s about ten percent smaller than our sun, and not even half as bright — kinda like my cousin Beau." Clete winked at the camera. He rummaged around in the fruit bowl and found a cherry. "And C — well, shoot, C’s just a l’il peckerwood of a star, a cold, dim red dwarf. Dang thing’s so small and dim, nobody even noticed it was there till 1911."

"Now, A and B — they orbit ’round each other like this." He moved the grapefruit and the orange to demonstrate. "But the distance between ’em ain’t constant." The sound of a buzz saw had started in the background.