‘I know already.’ This quite matter-of-factly.
He was intrigued. ‘So, tell me.’
Her smile turned secretive. ‘Not yet. I’m saving that for the finale.’ She lifted his list of targets and slipped it back into his folder. ‘But I will tell you exactly what it is I just put you through. And why.’ She adopted her sitting position on the edge of the desk again, her legs stretched out in front of her, arms folded. ‘It’s just a demonstration program,’ she said, ‘but basically it consists of me showing you fifty-four images. Nine of these are what we call probes. That is to say, they relate specifically to the crime that three of you were briefed on. Images that you would recognise instantly if you were one of those three. Another nine of the fifty-four were the targets that I gave you a list of. Each target corresponds to one of the probes. For example, your apartment block would correspond to the private dwelling house where the murder took place. You recognise your apartment block, and if you are one of those briefed, you recognise the murder house. Your brain emits the same recognition signal, the same MERMER.’
‘What about the other thirty-six?’
‘Irrelevants. That’s what we call them, because that’s what they are. Irrelevant. Although again, a number of them will correspond to the probes. So that you see your apartment block, the murder house, and some other apartment block that means nothing to you.’
The logic of it began to drop into place for Li. ‘Okay, I get it,’ he said. ‘You use my apartment block as the benchmark. The thing you know is familiar to me. If you get the same reading from the murder house, you know I’ve been briefed. But if the murder house and the irrelevant apartment block give the same reading, which is different from my apartment, you know I haven’t.’
She half-nodded, half-shrugged. ‘I guess that comes somewhere close to it. I would probably have said that the determination of guilt or innocence consists of comparing the probe responses to the target responses, which contain a MERMER, and to the irrelevant responses, which do not.’
Li let the implications tumble around in his mind. ‘That’s extraordinary,’ he said finally. ‘If it works.’
‘Oh, it works.’
‘You would know beyond doubt that a guilty suspect had knowledge of a crime scene that only the culprit could possess. And you could instantly rule out an innocent suspect if you could demonstrate that they had no recognition of specific elements of the crime or the crime scene.’
‘Which has been done,’ Pan said. ‘In the States. Where Doctor Farwell demonstrated to an appeal court that a man who had served twenty-two years of a prison sentence for murder had no details of the crime scene stored in his brain, while the details of his alibi were. And that evidence was ruled admissible by the judge.’ She laughed to herself. ‘Unlike poor old Bill Hart’s dinosaur technology. I can’t think of a single court anywhere that accepts the polygraph test as evidence.’
‘You don’t think much of the polygraph, then?’
‘I don’t. In a conventional polygraph test, emotion-driven physiological responses to relevant questions about the situation under investigation are compared to responses to control questions which are invasive and personal and not relevant to the issue at hand. Their only purpose is to emotionally and psychologically disturb the subject. So even if the subject is innocent, and truthful, he is subjected to a highly invasive and stressful ordeal. I don’t think you could say that about the MERMER test, do you?’
Li had to agree. ‘Not at all.’
‘The trouble with the polygraph, Section Chief, is that it’s not science. It’s artful and disturbing psychological manipulation.’
Li blew air through pursed lips. ‘You and Margaret would get on like a house on fire.’
Pan inclined her head. ‘Margaret…’ she repeated the name. ‘Campbell?’ Li nodded. ‘She’s quite a character, I hear. I’d like to meet her.’
‘If you can make it tonight you will.’ He stood up, his height restoring the mantle of dominance she had taken from him and worn herself during the test. But she didn’t seem to mind. The warmth in her eyes as they met his was unmistakable, and the twinkle in them suggested she was flirting.
‘I will do my very best to be there,’ she said. She stretched out a hand to shake his, and held it as she spoke. ‘It’s been a real pleasure, Section Chief.’
III
Margaret watched as a mother lifted her child into the shiny brass seat of the rickshaw. The little girl was perhaps three years old, drowned by a quilted red jacket, a sparkling red band keeping her long, black hair out of her face. Thousands of backsides had polished the seat to a brilliant shining gold. The rest of the life-sized statue was tarnished and dull, including the rickshaw man with his shaved pate and his long pigtail. A camera flashed in the afternoon sunshine. A few yards away a middle-aged man swept his hair self-consciously to one side as he posed for his wife’s camera with a couple of brass musicians. A man with a suit and an umbrella stood beside a brass barber shaving the head of an eternally acquiescent client. A half-empty open-sided blue tourist bus crawled past, the tour guide barking the history of Wangfujing Street through a speaker system that filled the air. The name Wangfujing derives from a fifteenth century well…No one was listening.
Beijing’s best-known shopping street had changed almost beyond recognition since Margaret had first kept an appointment there with Li Yan outside the Foreign Language Bookstore more than five years before. Vast new shopping complexes in pink marble had risen from the rubble of the old. Giant TV screens played episodes of a popular soap opera. Crowds of affluent Chinese, the new bourgeoisie, roamed the pedestrian precincts viewing luxury goods behind plate-glass windows, anxious to spend their new-found wealth. On the corner of Wangfujing and Donganmen, outside the bookshop, an old man wearing a cloth cap and dark blue cotton jacket pedalled up on his tricycle with a steaming urn to warm the young security men on traffic duty with mugs of hot green tea. They gathered around him like children, with their red armbands, laughing and giggling and poking each other while traffic at the junction ground to a halt.
Margaret smiled. While so much about China had changed in just five years, the character of the Chinese had not. There was something irresistibly likeable about them — unless you happened to be trying to renew your visa. The thought clouded her afternoon with memories of that morning’s debacle. She tipped Li Jon’s buggy on to its back wheels and bumped it up the two steps to the open doors of the bookstore, brushing aside the heavy strips of clear plastic that kept in the heat. An overhead heater blasted them with hot air, and Margaret turned off to their right where she knew they kept the stands of English language fiction and nonfiction books. Rows of shelving between grey marble pillars delivered books on every aspect of foreign language and culture to an increasingly literate population, hungry to feed a new-found appetite for learning about the world beyond the Middle Kingdom. People spoke here in hushed and reverent tones, in direct contrast with the cacophony in the street outside.
Margaret found what she was looking for on the middle shelf of the back wall. There were two English-language originals of Thomas Dowman’s The Murders of Jack the Ripper sitting side by side. She lifted one and found an assistant who wrote her out a slip in exchange for the book. She spotted a manned cash desk on the far side of the shop and took her slip there to pay for the book, before returning with her receipt to collect it from the assistant. It was tiresome, but it was the Chinese way, and you just got used to it. And it was also, she supposed, one way of keeping the unemployment figures down.