For my agent, Russell Galen, who picked Achilles' other choice

The Skydiver 7 had been filled with the soft sounds of beeping instruments and the ominous rumbling of the windstorm outside when Jakob Faraday had finally drifted off to sleep. Now, seven hours later, the storm was still raging against the probe's thick hull. But a new sound had also been added to the mix: a low but pervasive humming.

"Welcome back to the edge of the envelope," Scotto Chippawa greeted him as Faraday eased through the narrow doorway into the cramped control cabin. "Up a little early, aren't we?"

"Couldn't sleep," Faraday said, sliding into his chair beside the older man, listening to the faint whirring from his power-assist exoskeleton as he awkwardly strapped himself in. The gravity suit was a supreme nuisance, he'd long ago decided, and not nearly as user-friendly as its designers probably thought. But moving around down here in Jupiter's two and a half gees would be well-nigh impossible without it. "How are things going?"

"About the same as when you left," Chippawa said. "The wind's eased up a little, and the temperature's passed three hundred Kelvin on its way up again. Coffee?"

"Sure," Faraday said. "Double latte, easy on the cinnamon, with double cream."

"Right," Chippawa commented dryly. "Nearest latte's currently—" he peered at one of the displays

"—a hundred thirty klicks straight up. Help yourself."

"Don't think I'm not tempted," Faraday grunted, swiveling his chair around to the zero-gee coffee pot in its heating niche behind him. So they'd descended another forty kilometers since he'd toddled off to bed. That put them well into Jupiter's troposphere, not to mention within striking range of the record depth Keefer and O'Reilly had made it to last year. "I missed the rest of the cloud layers?"

"Slept right through them," Chippawa said cheerfully. "Don't worry, you'll get to see them again on the way up."

"Right," Faraday muttered, trying not to think about the hairline cracks the techs had found in Keefer and O'Reilly's probe after their dive. "I'll look forward to it."

He went through the unnecessarily complicated routine of drawing a cup of coffee from the zero-gee pot into his zero-gee mug. Another supreme nuisance, but one they also had no choice but to put up with. The Jovian atmosphere was about as calm and peaceful as one of the Five Hundred's budgeting sessions, and the pixel-pickers on Jupiter Prime got very upset when their glorified babysitters spilled coffee on expensive electronics.

Especially given the current funding battles the Jupiter Sector was having back on Earth. The Five Hundred, that oligarchy of the rich and powerful who effectively ran the Solar System, were constantly pushing humanity's boundaries outward, pressing on to new frontiers almost before the homesteading stakes had been driven into the ground of the last hard-fought conquest. With their attention now turned to new colonization efforts on Saturn's moons, Jupiter's interests and struggles were starting to get lost in the shuffle.

"By the way, Prime won't like it if they find out you shaved an hour off your sleep period,"

Chippawa commented. "They're very strict about the eight-hour rule."

"What was I supposed to do?" Faraday countered, sipping carefully at the brew. Fortunately, there wasn't a lot even Chippawa could do to ruin instant coffee. "Just lie there and stare at the ceiling?"

"Sure," Chippawa said with a power-assisted shrug. "That's what the rest of us do."

Faraday sniffed. "I guess I'm just too young and idealistic to sluff off that way when there's work to be done."

"Of course," Chippawa said. "I keep forgetting."

"It's that old-age thing," Faraday added soothingly. Chippawa was, after all, nearly fifty. "Memory always goes first."

"Yes, but at least I sleep well," Chippawa said pointedly.

Faraday grimaced. "It always feels like there's a sumo wrestler sitting on my chest whenever I lie down," he said. "I just can't sleep on these things."

"You'll get used to it," Chippawa assured him. "Somewhere around your fifth or sixth tether ride."

"If I last that long," Faraday said. "When did we pick up that humming noise?"

"About two hours ago," Chippawa said. "Prime thinks it's the wind hitting some sort of resonance with the tether."

Involuntarily, Faraday glanced up at the cabin ceiling. "Terrific," he said. "You ever hear of the Tacoma-Narrows Bridge?"

"I took the same physics courses you did," Chippawa reminded him. "Saw the same old vids, too.

But this isn't that same kind of resonance."

"You hope," Faraday said, tapping a fingernail surreptitiously on the polished myrtlewood finger ring his mother had given him when he graduated from high school. Not that he was superstitious or anything; but the image of that bridge twisting and swinging in the breeze as the wind caught it just right, and eventually coming completely apart, had haunted him ever since he saw it. "They will keep an eye on it, I presume?"

"What, with two hundred million dollars' worth of equipment on the line?" Chippawa asked, waving around. "Not to mention you and me?"

"Right." Taking another sip, Faraday gave the status board a quick check. Outside temperature was still climbing, wind speed was manageable, atmospheric composition was still mostly hydrogen with a pinch each of helium and methane mixed in. Hull pressure...

He winced and looked away. They were already at twenty bars, the equivalent of nearly two hundred meters below sea level on Earth.

Two hundred meters was nothing to an Earthbound bathyscaph, of course. But then, an Earthbound bathyscaph didn't also have to put up with heavy radiation and a magnetic field that could unscrew the ratchets on a socket wrench.

He'd seen the specs on the Skydiver's design, fine-tuned somewhat since Keefer and O'Reilly had taken their plunge, and he knew how much pressure it could handle. Even so, the actual raw numbers still left his stomach feeling a little queasy. He lifted his cup to his lips—

And at that precise second, something slammed into the side of the probe.

"Sheester's Mother," Chippawa swore, grabbing for the stabilizer controls.

"What was that?" Faraday managed as his coffee tried to go down the wrong tube. Trained reflexes set in, sending his cup flying as he grabbed at his own controls and checked the emergency board.

No hull breach; no oxygen tank or fuel-cell rupture; no hint of any other equipment malfunction.

"Sheester's Mother," Chippawa repeated, almost reverently this time. Faraday looked up—

And caught his breath. There, floating outside the thick Quadplexi window, squarely in the center of the probe's external lights, was a two-meter-long solid object. It looked something like a cross between a dolphin and a very large, very fat manta ray with a pair of long tails trailing behind it.

And as he watched, it rolled over and flapped away through the roiling atmosphere, its twin tails beating rhythmically at the air. A second later, two more of them swam into view around the sides of the probe and charged off after the first.

Slowly, Faraday turned to look at Chippawa. Chippawa was looking back at him.

Chippawa said it first. "I guess Keefer wasn't imagining things," he said, his voice studiously casual.

Faraday nodded, all the data from all of the manned and unmanned probes for all of the past twenty years flashing through his mind There was no life on Jupiter. None. Zip, zero, nada. All the books, all the studies, all the experts agreed on that.