The Core was a compact mass clustered about its black hole, a flattened sphere fifty miles wide. And, indeed, it was a world rendered in shades of red and pink. Its surface layers — subjected, Rees estimated, to many hundreds of gravities — were well-defined and showed almost topographical features. There were oceans of some quasi-liquid material, thick and red as blood; they lapped at lands that thrust above the general spherical surface. There were even small mountain ranges, like wrinkles in the skin of a soured fruit, and clouds like smoke which sped across the face of the seas. There was continual motion: waves miles wide crisscrossed the seas, the mountain sheets seemed to evolve endlessly, and even the coasts of the strange continents writhed. It was as if some great heat source were causing the Core's epidermis to wrinkle and blister constantly.

It was like Earth taken to Hell, Rees thought.

Hollerbach was ecstatic. He peered into the monitor as if he wished he could climb through it. "Gravitic chemistry!" he croaked. "I am vindicated. The structure of that fantastic surface can be maintained solely by the influence of gravitic chemistry; only gravitic bonds could battle against the attraction of the black hole."

"But it all changes so rapidly," Rees said.

"Metamorphoses on a scale of miles, happening in seconds."

Hollerbach nodded eagerly. "Such speed will be a characteristic of the gravitic realm. Remember that changing gravity fields propagate at the speed of light, and—"

Jaen cried out, pointing at the monitor plate.

At the center of one of the amorphous continents, etched into the surface like a mile-wide chessboard, was a rectangular grid of pink-white light.

Ideas crowded into Rees's mind. "Life," he whispered.

"And intelligence," Hollerbach said. "Two staggering discoveries in a single glance…"

Jaen asked, "But how is this possible?"

"We should rather ask, 'why should it not be so?' " Hollerbach said. "The essential condition for life is the existence of sharp energy gradients… The gravitic realm is one of fast-evolving patterns; the universal principles of self-organization, like the Feigenbaum series which govern the blossoming of structure out of chaos, almost demand that organization should arise."

Now they saw more gridworks. Some covered whole continents and seemed to be trying to buttress the "land" against the huge waves. Road-like lines of light arrowed around the globe. And — at the highest magnification — Rees was even able to make out individual structures: pyramids, tetrahe-dra and cubes.

"And why should intelligence not arise?" Hollerbach went on dreamily. "On a world of such violent change, selection in favor of organizing principles would be a powerful factor. Look how the gravitic peoples are struggling to preserve their ordered environments against the depredations of chaos!»

Hollerbach fell silent, but Rees's mind raced on. Perhaps these creatures would build ships of their own which could travel to other hole-based "planets," and meet with their unimaginable cousins. At present this strange biosphere was fueled by the influx of material from the Nebular debris cloud — a steady rain of star wrecks arcing on hyperbolic trajectories into the Core — and from within by the X-radiating accretion disc around the black hole, deep within the Core itself; but eventually the Nebula would be depleted and the gravitic world would be exposed, naked to space, fueled only by the heat of the Core and, ultimately, the slow evaporation of the black hole itself.

Long after all the nebulae had expired, he realized, the gravitic people would walk their roiling worlds. With a sense of dislocation he realized that these creatures were the true denizens of this cosmos; humans, soft, dirty and flabby, were mere transient interlopers.

Closest approach neared.

The Core world turned into a landscape; passengers screamed or sighed as the Bridge soared mere tens of miles above a boiling ocean. Whales drifted over the seas, pale and imperturbable as ghosts.

Something was tugging at Rees's feet. Irritated, he grabbed a Telescope strut and hauled himself back to the monitor; but the pull increased remorselessly, at last growing uncomfortable…

He began to worry. The Bridge should be in virtual free fall. Was something impeding it? He peered around the transparent hull, half-expecting — what? That the Bridge had run into some glutinous cloud, some impossible spout from the strange seas below?

But there was nothing.

He returned his attention to the Telescope — to find that Hoilerbach was now upside down; arms outstretched he clung to the monitor and was gamely trying to haul his face level with the picture in the plate. Bizarrely, he and Rees seemed to be being pulled toward opposite ends of the ship. Nead and Jaen were similarly arrayed around the Telescope mount, clinging on in the presence of this strange new field.

Screams arose around the chamber. The flimsy structure of ropes and sheets began to collapse; clothes, cutlery, people went sliding toward the walls.

"What the hell's happening, Hoilerbach?"

The old Scientist clenched and unclenched his hands. "Damn it, this isn't helping my arthritis—"

"Hollerbach…!"

"It's the tide!" Hollerbach snapped. "By the Bones, boy, didn't you learn anything in my orbital dynamics classes? We're so close to the Core that its gravity field is varying significantly on a scale of a few yards."

"Damn it, Hollerbach, if you knew all about this why didn't you warn us?"

Hollerbach refused to look abashed. "Because it was obvious, boy…! And any minute now we'll get the really spectacular stuff. As soon as the gravitational gradient exceeds the moment imposed by air friction — ah, here we go…"

The image in the monitor blurred as the Telescope lost its lock. The churning ocean wheeled over Rees's head. Now the shanty construction collapsed completely and bewildered passengers were hurled about; spatters of blood appeared on flesh, clothes, walls.

The ship was turning.

"Nose down!" Hollerbach, hands still clamped to the Telescope, screamed to make himself heard. "The ship will come to equilibrium nose down to the Core—"

The prow of the ship swung to the Core, ran past it, hauled itself back, as if the Bridge were a huge magnetized needle close to a lump of iron. With each swing the devastation within the Chamber worsened; now Rees could see limp bodies among the thrashing passengers. Absurdly, he was reminded of the dance he had watched in the Theater of Light; like dancers Bridge and Core were going through an aerial ballet, with the ship waltzing in the black hole's arms of gravity.

At last the ship stabilized, its axis pointing at the Core. The passengers and their effects had been wadded into the ends of the cylindrical chamber, where the tidal effects were most strong; Rees and the other Scientists, still clinging to the Telescope mount, were close to the ship's center of gravity, and were, Rees realized, escaping comparatively lightly.

Blood-red oceans swept past the windows.

"We must be near closest approach," Rees shouted. "If we can just survive the next few minutes, if the ship holds together against this tide—"

Nead, arms twined around the shaft of the Telescope, was staring at the Core ocean. "I think we might have to survive more than that," he said.

"What?"

"Look!" Nead pointed — and, his grip loosened, he slipped away from the Telescope. He scrabbled against the sheer surface of the instrument, hands trying to regain their purchase; then his grasp failed completely. Still staring at the window he fell thirty yards into the squirming mass of humanity crushed into one end of the cylindrical chamber.

He hit with a cracking sound, a cry of pain. Rees closed his eyes.

Hollerbach shouted urgently, "Rees. Look at what he was telling us."