"It's falling apart," Luca said.

"What is?"

"All of this." The stare he turned on the girl seemed heavy with too much knowledge and a realization that he'd never reach wherever it was he once thought he was going. "I'm sorry it's not better."

Luca looked so sad that Tris decided she probably had to sleep with him. It wouldn't be her first time and Tris wasn't worried about getting pregnant because Luca was obviously other than human and the mix never took in cases like that.

This piece of information came from Doc Joyce. And though the Doc had talked about exceptions, Tris felt it unlikely that Luca would carry the kind of germline fix needed to let him father children on stray humans... Of course, Tris didn't exactly think like this. She just thought, It's not going to happen.

And somehow that was enough.

"You own a bath?"

Luca's face froze and it took Tris a second to realize she'd just offended him. "I'm not saying you need one," she said hurriedly. "I mean, I've never had a bath. So if you've got one can I borrow it?"

"It's been a while," Luca said.

"What has?"

"Since I talked to anyone alive."

Tris decided not to think too deeply about that. Nodding at a random door, she said, "Through there...?"

"Sure," said Luca. "Why not?"

When Tris reached the doorway the room on the other side was busy rearranging itself, a divan melting into a wall as floor tiles stretched and sank to produce a bath twice her length.

"Too large," said Luca behind her and the tiles shifted again. "You'll still need some water," he said. "There should be water."

He led Tris to a courtyard where a huge cauldron stood, filled to the brim with rainwater. The cauldron was green with verdigris and the dragons that supported it had oxidized so badly in the rain that their scales were almost flat.

Below the cauldron stood a hearth heaped with ashes and when Luca swept these away Tris could see filaments of gold, some of which had melted and run together.

"We'll need some wood," Luca said. Instead of heading for a log pile, he wandered back into the pavilion, grabbed a gilded stool and smashed it hard against a doorpost. Scars on the post suggested this wasn't the first time it had been used that way.

"Try the table," suggested Luca.

Made from a honey-dark wood new to Tris, the table's top was carved into an ornate and aerodynamically sleek dragon, with vast wings which caught the wind like sails. On the back of the beast was a monk whose robes, beads and beard fluttered in the slipstream.

"Yes," said Luca, "that one."

So Tris picked up the table and carried it to the door. "It's beautiful," she said.

"Isn't it?" agreed Luca. "Here, let me." Taking the table from Tris's hands, he swung it hard into the doorpost, cracking monk and dragon into three. "It's not hard when you know how," he said. "The trick's in the wrist."

A temple carving followed the table, reduced to tinder in a single swing. "That should do us for now," said Luca.

To build his fire, Luca simply banked up fragments of table around a core of temple carving. And when both wood and kindling were ready, he flicked the fingers of his right hand across his thumb, like flint across steel.

"The water will take about a minute," he promised.

"How...?"

"The cauldron multiplies the heat. Whatever the cauldron takes in, it gives out more."

"That's impossible," said Tris.

"Most things are," Luca said, "if you think about them for long enough."

Kneeling next to the kindling, he reached out and Tris watched fire dance from his fingertips, catching ragged wood on a fragment of screen and turning those edges to gold.

"Watch," he said.

Flames caught the splintered screen and fire soon licked the underneath of the ancient cauldron, sliding up its sides until the flames grew, lost colour and disappeared into a heat so hot it was sufficient to make Tris stand back a little. All the same, the flames were nothing compared to the quantity of cold water in the cauldron and yet the inside rim was already beginning to birth bubbles, which grew fatter and fatter, until suddenly the whole slick surface began to roil and break.

"You'll need a bucket," Luca said, "to carry the hot water... We used to have servants," he added, "but they died." Seeing Tris's slight nod, Luca hesitated. "Did I tell you that already?" he said

Only Tris had stopped listening. She stood in the doorway of the pavilion looking bemused.

"The table..."

It was back, not yet complete but soft-edged and almost. A wax sculpture of woodwork melted by the sun. On the wall, a gold and red oblong was coalescing into a temple carving, its gold leaf and red undercoat becoming crazed with age.

"How?" the girl demanded.

"This is what the house does," Luca said. "Endlessly and always the same... Until something gives and suddenly a fire no longer lights itself or the shutters begin to ignore the rain. It will die eventually," he added, his voice entirely matter-of-fact, "but probably not before I do."

Tipping the first bucket into the bath, Luca went back for another. He worked with the rhythm of someone used to the world he inhabited, his life worn loosely.

"How old are you?" Tris asked. The question had been worrying her.

"You know," said Luca, as he scooped another bucket into the cauldron, "it's hard to say." He lifted the full bucket without appearing to notice its weight and carried it through the doorway in which she stood.

"Why is it hard?"

Luca shrugged and as he passed Tris on his way back their eyes met. It was nothing significant. Luca was just doing his best not to look at her breast where the top had torn. "Not sure I can answer that either," he said, sounding embarrassed for the first time since they'd met. "We live time differently."

"How do you live it?"

Like that, he wanted to say. Except this would be wrong, because the water in the cauldron boiled so simply, bubbles rising and currents defined by convection, properties of matter and the shape of the vessel in which it was all held. Time worked in all directions but was lived by humans only in one. At least that was what Luca had been taught.

And there were other differences. The girl's brain contained no pain fibres, for her, synaptic action was a pain-free process. Her brain could rot and she'd feel nothing. When Luca said a thought hurt he meant it.

"I live it one way," he said, "you another." Scooping up water, he carried his bucket into the pavilion, poured it into the bath and came out again. After that Luca worked in silence until the bath was full. "All yours," he said.

The girl glanced doubtfully at steam rising from the surface.

"No problem," Luca assured her, "the temperature will adjust. Well, it should do, unless that's stopped working as well."

In the end Tris tried the water with one toe, and then, when she realized Luca didn't intend to leave, she stripped off her ragged top, shook herself free from the trousers and stepped into her bath.

"Can you make me more clothes?"

"Maybe the house can," Luca said. "Whether you'll want to wear them..." And then he smiled, his gaze catching the latex rags she'd kicked into one corner of the room. "I'll see what we can do," he said, and with that he was gone, leaving the girl to soak away her doubts.

Tris said later, mostly to herself, that she couldn't remember why she agreed to sex. Although this was inaccurate because Tris was the one who instigated it by climbing from her bath and walking naked through the pavilion until she finally found Luca in an attic room, drawing something on a long scroll of paper. An ink stone and mixing pot stood beside him and a small bamboo brush was held elegantly in one hand.

"CV-1," he said blushing.