"Something I can do for you?"

He came around until he could see the box, which had a picture flickering dimly on one side of it.

"What's that?"

"Old-timey television," she said. "Honey West, circa 1965, American Broadcasting Company.

Starring Anne Francis, John Ericson, and Irene Hervey, Friday nights at 2100. Spin-off from Burke's Law, died 1966. What's up?"

"What's wrong with the depth?"

"They didn't have it." She removed her glasses and began to chew absently on one rubber tip. "How are you doing?"

"I'm surprised to see you wear glasses."

"When you've had as many operations as I have, you skip the ones you think you can do without.

Why is it I sense you're having a hard time saying whatever it is you came here to say?"

"Would you like to go for a swim?"

"Pool's closed. Weekly filtering, or something like that."

"I know. Best possible time to go for a swim."

She frowned. "But I was told no one is admitted during the filtering."

"Yeah. It's illegal. Isn't everything that's fun?"

The Bubble was closed one hour in every twenty-four for accelerated filtering. At one time the place had been open all day, with filtration constantly operating, but then a client got past the three safety systems, where he was aerated, churned, irradiated, centrifuged, and eventually forced through a series of very fine screens. Most of him was still in the water in one form or another, and his legend had produced the station's first ghost.

But long before the Filtered Phantom first sloshed down the corridors the system had been changed.

The filters never shut down completely, but while people were in the pool they were operated at slow speed. Once a day they were turned to full power.

It still wasn't enough. So every ten days BCE closed the pool for a longer period and gave the water an intensive treatment.

"I can't believe no one even watches it," Megan whispered.

"It's a mistake. Security is done by computer. There's twenty cameras in here but somebody forgot to tell the computer to squeal if it sees anybody enter during filtration. I got that from the computer itself, which thinks the whole fuck-up is very funny."

The hordes of swimmers had been gone for over two hours, and the clean-up crew had left thirty minutes before. Megan Galloway had probably thought she knew the Bubble pretty well, on the basis of her two visits. She was finding out now, as Cooper had done long ago, that she knew nothing. The difference between a resort beach on a holiday weekend and on a day in mid-winter was nothing compared to what she saw now.

It was perfectly still, totally clear: a crystal ball as big as the world.

"Oh, Cooper." He felt her hand tighten on his arm.

"Look. Down there. No, to the left." She followed his pointing finger and saw a school of the Bubble goldfish far below the surface, moving like lazy submarines, big and fat as watermelons and tame as park squirrels.

"Can I touch it, daddy?" she whispered, with the hint of a giggle. He pretended to consider it, then nodded. "I almost don't want to, you know?" she said. "Like a huge field covered in new snow, before anybody tracks across it."

"Yeah, I know." He sighed. "But it might as well be us. Hurry, before somebody beats you to it." He grinned at her, and pushed off slowly from his weightless perch on the sundeck tier that circled the rim of the champagne glass.

She pushed off harder and passed him before he was halfway there, as he had expected her to. The waves made by her entry spread out in perfect circles, then he broke the surface right behind her.

It was a different world.

When the Bubble had first been proposed, many years before, it had been suggested that it be a solid sphere of water, and that nothing but weightlessness and surface tension be employed to maintain it.

Both forces came free of charge, which was a considerable factor in their favor.

But in the end, the builders had opted for TDF fields. This was because, while any volume of water would assume a spherical shape in free-fall, surface tension was not strong enough to keep it that way if it was disturbed. Such a structure would work fine so long as no swimmers entered to upset the delicate balance.

The TDF's provided the necessary unobtrusive force to keep things from getting messy. Tuned to attract or repel water, they also acted to force foreign matter toward either the inner or outer surfaces; in effect, making things that were not water float. A bar of lead floated better than a human body. Air bubbles also were pushed out. The fields were deliberately tuned to a low intensity. As a result, humans did not bob out of the water like corks but drifted toward a surface slowly, where they floated quite high in the water. As a further result, when the pool was open it was always churned by a billion bubbles.

When Cooper and Galloway entered the water the bubbles left behind by the happy throngs had long since merged with one of the larger volumes of air. The Bubble had become a magic lens, a piece of water with infinite curvature. It was nearly transparent with an aquamarine tint. Light was bent by it in enchanting ways, to the point that one could fancy the possibility of seeing all the way around it.

It distorted the world outside itself. The lifeguard station, cabanas, bar, and tanning chairs in the center were twisted almost beyond recognition, as if vanishing down the event horizon of a black hole. The rim of the glass, the deep violet field-dome that arched over it, and the circle of tanning chairs where patrons could brown themselves under genuine sunlight bent and flowed like a surrealist landscape. And everything, inside and outside the Bubble, oozed from one configuration to another as one changed position in the water. Nothing remained constant.

There was one exception to that rule. Objects in the water were not distorted. Galloway's body existed in a different plane, moved against the flowing, twisting background as an almost jarring intrusion of reality: pink flesh and golden metal, curly yellow hair, churning arms and legs. The stream of air ejected from her mouthpiece cascaded down the front of her body. It caressed her intimately, a thousand shimmering droplets of mercury, before it was thrashed to foam by her feet.

She moved like a sleek aerial machine, streamlined, leaving a contrail behind her.

He customarily left his mouthpiece and collar-tank behind when he swam alone, but he was wearing it now, mostly so Galloway would not insist on removing hers, too. He felt the only decent way to swim was totally nude. He conceded the breathers were necessary for the crustaceans and plankton who did not understand the physical laws of the Bubble and who would never take the time to learn them. It was possible to get hopelessly lost, to become disoriented, unable to tell which was the shortest distance to air. Though bodies would float to a surface eventually, one could easily drown on the way out. The Bubble had no ends, deep or shallow. Thus the mouthpieces were required for all swimmers. They consisted of two semi-circular tanks that closed around the neck, a tube, a sensor that clipped to the ear, and the mouthpiece itself. Each contained fifteen minutes of oxygen, supplied on demand or when blood color changed enough to indicate it was needed. The devices automatically notified both the user and the lifeguard station when they were nearly empty.

It was a point of honor among the lifeguards to turn them in as full as they had been issued.

There were things one could do in the Bubble that were simply impossible in flat water. Cooper showed her some of the tricks, soon had her doing them herself. They burst from the water together, described long, lazy parabolas through the air, trailing comet tails of water. The TDF fields acted on the water in their bodies at all times, but it was such a lackadaisical force that it was possible to remain in the air for several minutes before surrendering to the inexorable center-directed impulse.