"So," said the young servitor, as he casually broke a piece of crust off a deep-fried huntun and fed it to his rat, "what do you think?" But Null merely wrinkled its whiskers and looked round for more.

After the rat had dined on the oily edges, its master ate what was left of the filo base and most of the chilli and chicken filling, chewing the food with interest as he slid the rat back into his sleeve and rearranged the dim sum so that the plate still looked full.

"For the Emperor," he told a guard, and the man stepped back from a gold, red and green arch which was decorated with calligraphic banners praising the Chuang Tzu as the intermediary of heaven.

"For the Emperor..." Having called out these words, the man slammed his halberd into the tiles so hard that the weapon almost bounced out of his hand.

The interloper expected to find more guards in the Hall of Union but instead he found himself alone, facing a wooden throne. The throne was gilded, flanked by four lesser thrones, two on either side and all positioned a pace behind the throne of the Emperor. For reasons which were not immediately clear the lesser thrones were hidden under silk. Only the central one was uncovered.

It fitted him perfectly.

"You shouldn't be sitting there."

"Tell me about it," said the servitor and the voice in his head laughed a little sadly, or maybe it was bitterly. The servitor had always known that it was not really a voice, merely what his mind translated as a voice. It had been a long time since he'd expected other people to hear the things he heard.

Directly over the dais on which the throne sat was a panel painted with cryptograms representing Wu Wei, the fundamental Taoist principle of responding spontaneously and fluidly to any circumstance.

Above the panel hung a ceiling so ornate it made the servitor's head spin just to look at the intricacy of the gilded carving. He could make out endless dragons and, he thought, a phoenix, but most of the central carving was geometric, endless repetitions of a simple form.

A pale silk carpet covered the dais but the actual floor of the pavilion was dark stone pitted with age and scuffed with the feet of nearly five thousand years of ambassadors presenting their credentials.

The twenty-seven most commonly used seals rested inside a glass cabinet, some were soapstone, a few sandalwood but most were jade. All but three were in Manchu, one of those being in a language no one had ever identified.

Watched by at least a billion the servitor carried his tray across the courtyard to the third and last of the private pavilions. Heavenly Purity housed another, significantly more important, seat of power, the Lesser Throne from which the Emperor greeted ambassadors on their first arrival.

It was in this pavilion that his concubines should live, in eighteen bedrooms, arranged nine on both sides, each bedroom containing three beds, fifty-four in all.

All but one were deserted.

And it was this last that the Emperor had made his own. Neither the servitor nor the billions watching knew which room housed the Chuang Tzu because the feed was strangely imprecise about this.

"For the Emperor," said the servitor.

The officers who moved to intercept him wore scale armour made from star-shaped pieces of what looked like steel sewn at the points to a silk jacket, each attachment being protected by the body of the star next to it. An intricate and time-consuming way to create armour. Except that the officers' armour was summer-weight, carbon-based and required no tempering. It still swallowed the light, though, and presented itself with a solidity belied by its actual lightness.

"From the kitchens," the servitor said, lifting his tray slightly higher. Stepping between the guards, he swept through a door that opened as if his entry was expected and found himself in an anteroom, facing another guard in armour even more light-swallowing than that of the men he'd just left behind.

General Ch'ao Kai watched the young man walk towards him across an unlit floor, while outside drizzle cut across Rapture's sky and a cold wind slid through the pavilion and ate into his bones, more potent than fear.

"Everything's going to be all right," the servitor said, and then he nodded, repeating himself in little more than a whisper as billions of watchers begged leave to disagree. He spoke, of course, to the rat now frozen within his sleeve, liking the darkness but made fearful by the levels of anxiety radiating from its master.

"Food for His Celestial Excellency."

The General inclined his head just enough to include the young man within his gaze. He was hereditary leader of the guard, custodian of the inner door and an elder clansman of a lesser banner. It was true he commanded few fighting troops but with no enemy these were unnecessary. Quarrels might happen between the 2023 worlds but the worlds themselves could not fight each other, since each was dependent on all others for the fine gravitational balance which kept them in stable orbit.

One of the earliest of the Chuang Tzu had made this clear. Besides, in an empire of plenty where was the need for violence? No single culture had ever monopolized all 2023 worlds but a constant homogenization now more or less guaranteed the cultural equivalent of convergent evolution. The smallest differences might still seem massively significant, but major differences had long since been etched smooth by familiarity and time.

"What do you have there?"

The servitor glanced down at his tray. Now seemed a good time to state the obvious. "Five different kinds of dim sum," he said. "This is har gao and this Szechwan huntun, that's char siu bao..." He counted off the tiny offerings one at a time, silently giving thanks to the absent sous chef.

In the end it was the tray rather than the food which persuaded General Ch'ao Kai that the man spoke the truth. Inlaid ebony and a single slab of flawless mutton-fat jade. Only an emperor would be served on such a tray.

"Are you expected?"

"I couldn't say."

"You...?"

"How would I know?" The young servitor shrugged and General Ch'ao Kai suddenly got a sense of having seen the man before. As the palace was as full of servitors as it was of eunuchs and the General made a point of paying less than zero attention to either, this seemed more than likely.

"Put down the tray," General Ch'ao Kai demanded, "then face the wall with your legs apart and your hands clasped behind your head."

"No," the servitor said. "I couldn't possibly do that."

"Why not?" General Ch'ao Kai was so shocked by the answer that he forgot to be furious, although a thin sliver of his mind retained the insult and readied itself to be offended.

"Because it would upset my rat," said the servitor, "that's one reason." Shaking his sleeve, he waited for a narrow white face to show its nose and whiskers. "This is Null," he said. "Unfortunately his sister died."

"Sister?"

"Void," said the servitor. "There's another reason," he added. "Slightly better. I'm not allowed to let this tray out of my hands."

"You're not--"

"In case the food is poisoned." His shrug was slight, an acknowledgment of the absurdity of this suggestion. "The order was very clear."

"And who gave this order?"

"The Library itself," said the boy, pretending not to notice a slight widening of General Ch'ao Kai's carefully kohled eyes. Only the Emperor spoke directly to the Library, its voice being the one single element missing from what watchers were allowed to experience of the Emperor's life inside the Forbidden City.

It spoke to the worlds, but only through the Librarian.

"You spoke to the avatar?"

"No, sir." The servitor shook his head.

General Ch'ao Kai had two choices. He could strike the servitor down for blasphemy or he could open the door. As well as being undignified, striking him down seemed unwise, particularly if the servitor was telling the truth.