The Quantum Thief

a gevulot mask is when he speaks to Isidore. And it is clear that he is able to alter his appearance at will. Distantly, he wonders if a part of the unease he feels is fear: perhaps le Flambeur is out of his league.

He stops for a moment under one of the Avenue’s cherry trees and breathes in the smell of the blossoms to clear his head. Nothing but reputation and a certain flair separate his enemy from any common gogol pirate. Somewhere, le Flambeur will have made a mistake, and Isidore is going to find it.

Gritting his teeth, he heads for the side alleys of the Avenue, to find a Watchmaker’s shop.

*

‘Interesting,’ says the Watchmaker, squinting at Unruh’s Watch through a massive brass eyepiece. ‘Yes, I think I can tell you how it was done.’

The eyepiece lens flickers with digital information. The Watchmaker is a lanky, middle-aged man in a black T-shirt with ripped sleeves, blue hair, a scraggly moustache and ears stretched by implants and earrings. His workshop is a cross between a quantum physics laboratory and a horologist’s workspace, full of sleek humming boxes with holodisplays hovering around them and neatly sorted piles of tiny gears and tools on wooden work surfaces. Violent music plays in the background, and the Watchmaker bops his head up and down frantically to its rhythm as he works. After Isidore told him the story of Unruh, he was more than happy to help, although it takes some effort to ignore the occasional lewd glance he casts at the young man.

He pulls something out of the Watch with the pincers that the fingers of his gloves end in, miniature hands with fingers extending to the molecular level. He holds it up against a light. It is barely visible, a tiny flesh-coloured spider. He places it into a tiny tempmatter bubble and magnifies it: it becomes an insectoid monster the size of a hand. Isidore takes out his magnifying glass, prompting a curious glance from the Watchmaker.

‘This baby here has EPR states in its belly,’ the Watchmaker says. ‘It wormed its way into the ion traps of the Watch where the Time credits are stored, got the stuff in its stomach entangled with the trap quantum states, sent out a signal of some kind – and bamf, the states got teleported away. Almost the oldest trick in the quantum mechanic’s handbook, although this is the first time I’ve seen it used to steal Time.’

‘Where would the receiver be?’ Isidore asks.

The Watchmaker spreads his hands. ‘Could be anywhere. Qupting does not need a strong signal. Could be in space, for all I know. This little bug is definitely not from around here, by the way. Sobornost, for my money.’ He spits to the floor. ‘I hope you catch ’em.’

‘Me too,’ Isidore says. ‘Thank you.’ He looks around the shop. There is something familiar about the Watches under the glass counter, something that tickles his mind—

A Watch. A heavy brass face. A silver band. The word Thibermesnil—

Where does the memory come from?

‘Are you all right, son?’ asks the Watchmaker.

‘Yes, I’m fine. I just need to sit down for a moment.’ Isidore sits down on the chair the quantum horologist offers. Closing his eyes, he revisits the exomemories from the party. There: a bizarre sense of seeing double, just after he spoke to the thief, just before he stole Time from Unruh. Of course: if the thief used Isidore’s own identity key to pretend to be him, he has access to the exomemories created during those moments.

‘Could you turn the music down, please?’

‘Sure. Sure. Would you like a glass of water?’

He massages his temples, carefully sifting through the memories, separating the ones that are his from the ones that should not be. He looked at his Watch. That is his Watch. And there are other thoughts there too, glimpses of architectural drawings, a beautiful woman with a scar on her face, and a butterfly- like spaceship with glittering wings. Emotion, too: arrogance and self-confidence and bravado that make him angry. I’m going to get you, he thinks. See if I don’t.

He opens his eyes, head pounding, accepts the offered glass and drinks deep. ‘Thank you.’ He takes a deep breath. ‘One more question, and then I’ll stop bothering you. Have you ever seen this Watch?’ He passes a co- memory of the Watch he just saw to the Watchmaker.

The man considers it for a moment. ‘Can’t say I have. But this looks like something that old Antonia would have made, two streets down. Tell her Justin sent you.’ He winks at Isidore.

‘Thank you again,’ Isidore says. ‘You have been a big help.’

‘Don’t mention it. It’s difficult to meet young people who appreciate Watches these days.’ He grins, putting his gloveless hand on Isidore’s thigh. ‘Although if you really want to show your appreciation, I’m sure there’s something we can come up with—’

Isidore flees. As he hurries down the street, the roar of the music starts again, mixed with laughter.

‘Yes, I remember this,’ says Antonia. She is not old at all, at least not in appearance: in her third or fourth body, perhaps, a petite dark-skinned woman with Indian features. Her shop is bright and orderly, with Xanthean designer jewellery displayed alongside the timepieces. She immediately printed out a tempmatter instantiation of the co-memory, weighing it in her hands, tapping it with a bright red fingernail.

‘It would have been years ago,’ she says, ‘twenty Earth years maybe, judging by the design. The customer wanted a special little mechanism, you could hide something inside it and open it by pressing a combination of letters. A gift to a lover, probably.’

‘Do you, by any chance, remember anything about the person who bought it?’ Isidore asks.

The woman shakes her head.

‘It’s shop gevulot, you know – we rarely get to keep that sort of thing. I’m afraid not. People tend to be very private about their Watches.’ She frowns. ‘However – I’m pretty sure there was a whole series of these. Nine of them. Very similar designs, all for the same customer. I can give you the schematics, if you like.’

‘That would be wonderful,’ Isidore says. Antonia nods, and suddenly his head is full of complex mechanical and quantum computing design diagrams, along with another headache jolt. As he blinks at the pain, Antonia smiles at him. ‘I hope Justin did not scare you,’ she says. ‘This is a lonely profession – long hours, not much appreciation – sometimes he gets a little carried away, especially with young men like you.’

‘Sounds like being a detective,’ Isidore says.

Isidore has lunch at a small floating restaurant in Mont-golfiersville and gathers his thoughts. Even here, he is recognised – apparently his involvement in Unruh’s carpe diem party has been prominently reported by the Herald – but he is too preoccupied with the Watches to hide from every curious glance with gevulot. Hardly tasting his pumpkin quiche, he goes through the designs in his mind.

They are all identical, except for the engravings. Bonitas. Magnitudo. Eternitas. Potestas. Sapientia. Voluntas. Virtus. Veritas. Gloria. Goodness, Greatness, Eternity, Power, Wisdom, Will, Virtue, Truth, Glory. None of them qualities he would immediately associate with Jean le Flambeur. But they do suggest that the Unruh affair was not some random impulse to play games with Oubliette barbarians, as the millenniaire suspected. Clearly, le Flambeur has some connection to Mars, one stretching back twenty years at least.

Drinking coffee and looking at the view of the city below, he spends an hour ’blinking at the words. In combination, they appear in medieval texts, Raymond Lull’s Dignities of God from the 13th century, with some connections to the sephiroths of Kabbalistic tradition and the lost art of … memory. One of Lull’s followers was Giordano Bruno, who perfected the art of memory palaces, of storing mental images in physical locations, as if outside the mind. That, at least, is a connection that resonates. The Oubliette exomemory does the same thing, stores everything thought, experienced and sensed in a location in the ubiquitous computing machinery around it.

The shape of it feels right, but he is not sure if it is just pattern matching, like seeing faces in the clouds. Then the memory fragment about the architectural drawings comes back.

Another ’blink – looking for memory palaces – reveals that there was a series of architectural pieces commissioned by the Voice twenty years ago. Nine reflections on memory, by an architect called Paul Sernine.

All the palaces are located in the Maze, relatively close to each other, but the public exomemories about them are old, and Isidore is forced to do some footwork to find them.

The first piece he comes across is near a Maze marketplace, squeezed between a synagogue and a small public fabber centre. It is completely bizarre. The size of a small house, it is made from some black, smooth material. It consists of geometric surfaces, planes, cubes, stuck together in a seemingly haphazard fashion: still, he