Rather to Poole's surprise, she agreed with his criticism.

'That may be true – in some respects. Perhaps we're physically weaker, but we're healthier and better adjusted than most humans who have ever lived. The Noble Savage was always a myth'.

She walked over to a small rectangular plate, set at eye-level in the door. It was about the size of one of the countless magazines that had proliferated in the far-off Age of Print, and Poole had noticed that every room seemed to have at least one. Usually they were blank, but sometimes they contained lines of slowly scrolling text, completely meaningless to Poole even when most of the words were familiar. Once a plate in his suite had emitted urgent beepings, which he had ignored on the assumption that someone else would deal with the problem, whatever it was. Fortunately the noise stopped as abruptly as it had started.

Dr Wallace laid the palm of her hand upon the plate, then removed it after a few seconds. She glanced at Poole, and said smilingly: 'Come and look at this.'

The inscription that had suddenly appeared made a good deal of sense, when he read it slowly:WALLACE, INDRA [F2970.03.11 :31.885 / /HIST.OXFORD] 'I suppose it means Female, date of birth 11 March 2970 – and that you're associated with the Department of History at Oxford. And I guess that 31.885 is a personal identification number. Correct?'

'Excellent, Mr Poole. I've seen some of your e-mail addresses and credit card numbers – hideous strings of alpha-numeric gibberish that no one could possibly remember! But we all know our date of birth, and not more than 99,999 other people will share it. So a five-figure number is all you'll ever need... and even if you forget that, it doesn't really matter. As you see, it's a part of you.'

'Implant?'

'Yes – nanochip at birth, one in each palm for redundancy. You won't even feel yours when it goes in. But you've given us a small problem...'