The Quantum Thief

The thought makes him blink. It is like saying that gravity might not be a constant 0.6g, or that the sun might not come up tomorrow. But the thought, wrong as it is, fits. And not only that, it feels like it is only a part of some larger shape, looming in the darkness, just beyond his grasp. When you eliminate the impossible, whatever remains, however improbable, must be the truth.

Something chilly touches his toes, and he lets out a small yelp. It is the creature, exploring the world under his blanket. He picks it up again and gives it an angry look. It flutters its tentacles innocently.

‘You know,’ Isidore says, ‘I think I’m going to call you Sherlock.’

As promised, she assists him in choosing an outfit for the carpe diem party. They spend half a day on Persistent Avenue. The celebration is going to be Time-themed, and a deft-fingered outfitter measures him up for a costume based around Sol Lunae, the second day of the Darian week: black and silver.

‘Isn’t the Moon supposed to be feminine?’ he protests when Odette informs him of the theme.

‘Christian has thought about this very carefully,’ Odette says, frowning as the shop projects various designs on Isidore’s lean frame. ‘I wouldn’t argue with him: I’ve never managed to change his mind. I think we are going to try another fabric, possibly velvet.’ She smiles. ‘The Moon also symbolises mystery, and intuition. Perhaps that is what you represent to him. Or perhaps not.’

Isidore stays quiet after that and submits to the gentle torture of the tailor without complaint.

After the shopping trip, he returns to the chateau and starts to eliminate the impossible, coming up with a series of hypotheses to explain the appearance of the letter, each more elaborate than the last. They range from self-assembling paper to an invisibility fog sophisticated enough to fool the ubiquitous exomemory sensors. But everything brings him back to the improbable conclusion: something is wrong with exomemory itself.

One of the Quiet servants brings him a light lunch, which he eats alone. Apparently, the millenniaire is too occupied with his last week in a Noble body to spend much Time on something already set in motion.

In the afternoon, Isidore considers the possibility of exomemory manipulation. He ’blinks until his head pounds with technical information about distributed ubiquitous communication and quantum public key cryptography, Byzantine general problems and shared secret protocols. The exomemory is everywhere. Its tiny distributed sensors – in every piece of smart- and dumbmatter – record everything, from events to temperature fluctuations to object movements to thoughts, with access to it controlled only by gevulot. But it has been designed to be write-only, with massive redundancy. Hacking into it and editing it would mean nanotechnological and computational resources far beyond the reach of any Oubliette citizen.

The realisation sends a chill down Isidore’s spine. Perhaps some otherworldly force has indeed chosen Unruh as its target.

After a walk in the garden – where a white-haired man in blue coveralls is working on Unruh’s flowers with the help of a Quiet servant – he goes through all of the castle exomemory he has access to, looking for other gaps. He sits in one of the library chairs, remembering. Unruh has had a regular life for the past year, almost hermit-like, apart from the occasional small party. There are times when exotic courtesans from Serpent Street pass through the memories, making Isidore wonder what Adrian Wu would make of his new patron. But mostly Unruh spends his time in solitude, receiving antique dealers, eating alone, and spending endless hours immersed in study in the library.

He is almost ready to give up – the amount of detail is too much to absorb on one sitting – when he decides to cross-reference the memory with the book Unruh was reading, the lifecast of Count Isidis. The last time Unruh read it was four weeks ago. And in the memory—

It takes a few moments to take in. Then he leaps to his feet and goes to find Odette. She is overseeing preparations for the party in a small office in the eastern wing of the chateau, surrounded by floating spime invitations, like a flock of birds frozen in time.

‘I want to see M. Unruh.’

‘I’m afraid that is not possible,’ she says. ‘Christian has only a few days left, and unless he tells me otherwise, he is going to spend them how he pleases.’

‘I have some questions for him.’