"Thank you," said Mr Standish with a slightly tense look. "And tidy up in here please. The place looks a - "

He wanted to say that the place looked a mess, but was frustrated by its air of clinical sterility.

"Just tidy up generally," he concluded.

"Yes, Mr Standish."

The psychologist nodded tersely, brushed a non-existent speck of dust off the top of his desk, flicked another brief smile on and off at Kate and then escorted her out of his office into the corridor which was immaculately laid with the sort of beige carpet which gave everyone who walked on it electric shocks.

"Here, you see," said Standish, indicating part of the wall they were walking past with an idle wave of his hand, but not making it in any way clear what it was he wished her to see or what she was supposed to understand from it.

"And this," he said, apparently pointing at a door hinge.

"Ah," he added, as the door swung open towards them. Kate was alarmed to find herself giving a little expectant start every time a door opened anywhere in this place. This was not the sort of behaviour she expected of a worldly-wise New Yorker journalist, even if she didn't actually live in New York and only wrote travel articles for magazines. It still was not right for her to be looking for large blond men every time a door opened.

There was no large blond man. There was instead a small, sandy-haired girl of about ten years old, being pushed along in a wheelchair. She seemed very pale, sick and withdrawn, and was murmuring something soundlessly to herself. Whatever it was she was murmuring seemed to cause her worry and agitation, and she would flop this way then that in her chair as if trying to escape from the words coming out of her mouth. Kate was instantly moved by the sight of her, and on an impulse asked the nurse who was pushing her along to stop.

She squatted down to look kindly into the girl's face, which seemed to please the nurse a little, but Mr Standish less so.

Kate did not try to demand the girl's attention, merely gave her an open and friendly smile to see if she wanted to respond, but the girl seemed unwilling or unable to. Her mouth worked away endlessly, appearing almost to lead an existence that was independent of the rest of her face.

Now that Kate looked at her more closely it seemed that she looked not so much sick and withdrawn as weary, harassed and unutterably fed up. She needed a little rest, she needed peace, but her mouth kept motoring on.

For a fleeting instant her eyes caught Kate's, and the message Kate received was along the lines of "I'm sorry but you'll just have to excuse me while all this is going on". The girl took a deep breath, half-closed her eyes in resignation and continued her relentless silent murmuring.

Kate leant forward a little in an attempt to catch any actual words, but she couldn't make anything out. She shot an enquiring look up at Standish.

He said, simply, "Stock market prices."

A look of amazement crept over Kate's face.

Standish added with a wry shrug, "Yesterday's, I'm afraid."

Kate flinched at having her reaction so wildly misinterpreted, and hurriedly looked back at the girl in order to cover her confusion.

"You mean," she said, rather redundantly, "she's just sitting here reciting yesterday's stock market prices?" The girl rolled her eyes past Kate's.

"Yes," said Standish. "It took a lip reader to work out what was going on. We all got rather excited, of course, but then closer examination revealed that they were only yesterday's which was a bit of a disappointment. Not that significant a case really. Aberrant behaviour. Interesting to know why she does it, but - "

"Hold on a moment," said Kate, trying to sound very interested rather than absolutely horrified, "are you saying that she is reciting - what? - the closing prices over and over, or - "

"No. That's an interesting feature of course. She pretty much keeps pace with movements in the market over the course of a whole day. Just twenty-four hours out of step."

"But that's extraordinary, isn't it?"

"Oh yes. Quite a feat."

"A feat?"

"Well, as a scientist,