'What's its capacity?' he asked. 'In my time, we were up to a terabyte in something this size. I'm sure you've done a lot better.'

'Not as much as you might imagine – there's a limit, of course, set by the structure of matter. By the way, what was a terabyte? Afraid I've forgotten.'

'Shame on you! Kilo, mega, giga, tera... that's ten to the twelfth bytes. Then the petabyte – ten to the fifteenth – that's as far as I ever got.'

'That's about where we start. It's enough to record everything any person can experience during one lifetime.'

It was an astonishing thought, yet it should not have been so surprising. The kilogram of jelly inside the human skull was not much larger than the tablet Poole was holding in his hand, and it could not possibly be as efficient a storage device – it had so many other duties to deal with.

'And that's not all,' the Brainman continued. 'With some data compression, it could store not only the memories – but the actual person.'

'And reproduce them again?'

'Of course; straightforward job of nanoassembly.'

So I'd heard, Poole told himself – but I never really believed it.

Back in his century, it seemed wonderful enough that the entire lifework of a great artist could be stored on a single small disk. And now, something no larger could hold – the artist as well.

7 – Debriefing

'I'm delighted,' said Poole, 'to know that the Smithsonian still exists, after all these centuries.'

'You probably wouldn't recognize it,' said the visitor who had introduced himself as Dr Alistair Kim, Director of Astronautics. 'Especially as it's now scattered over the Solar System – the main off-Earth collections are on Mars and the Moon, and many of the exhibits that legally belong to us are still heading for the stars. Some day we'll catch up with them and bring them home. We're particularly anxious to get our hands on Pioneer 10 – the first manmade object to escape from the Solar System.'