"We need you to be a Turing Observer." The man who spoke was quiet but authoritative, his manner suggesting subtly that he wasn't expecting me to say no. I looked at him again, my eyes raking across him as I tried to work out what I was talking to. He was wearing a dark-blue Italian wool suit with a nearly invisible pin-stripe and creases so sharp that they could only have been ironed in that morning. Or he was a robot and didn't fidget, sit awkwardly or do any of the other hundred small things that caused humans to rumple their clothes. His fingernails were manicured, so he either cared about his appearance – not unusual in his line of work – or he was a robot and they mostly kept themselves looking manicured. He was wearing a signet ring on the little finger of his left hand, which seemed quite human until you knew that a lot of robots were now copying humans for their outward appearances and had picked up on small, distinguishing things like jewellery, freckles and key-jangling as easy, low-cost ways to fit in better. His shoes were black and shiny enough to reflect nearby objects. His eyes were hazel and looked slightly too wet, but that could as easily be an eye infection. He was very, very hard to judge.
"What's one of those then?" I asked. I knew what a Turing Observer was, it was a human hired by the artificial intelligences that oversee Turing tests, checking that the test was conducted fairly and judged correctly. They claimed that there had to be both an AI and a human observer for fairness, but some of us knew that the real reason was that they were afraid that the humans were cheating. And there was the crux of the matter: the Turing Observer was never told if the test subject was human or robot, so if you declared the test failed, and the AI Observer agreed, you might just have declared a human incapable of appearing human.
It gave people nightmares, and they rarely lasted more than a month or two in the job. But if there were two AI observers, somehow the humans never failed, and the AIs had decided that the humans must be cheating somehow.
The man explained all this to me in clipped, dry tones, speaking a little bit fast, and hinting only very, very slightly at an accent. Italian, I thought. Again, it could be a robot, but it could also be what it appeared to be: a clever man with a lots of years of experience in dealing with people and handling difficult situations. No comment that I must know what a Turing Observer was, which suggested a lot of patience if he was truly human.
"Turing as in...?" I said, testing a little further.
"Alan Turing, the British – you know, we have run background checks on you. We know that you know all this. Do you really need to hear me tell you?"
"I guess not," I said, smiling. Again, borderline human/AI. "It's not a light decision to take," I said. "Would you like a coffee while I think about it?"
"I'm vegan," he said straight away. "I like coffee, but it would need to be fairtrade really."
"They serve Kopi Luwak," I said, "though it's incredibly expensive. You can't get much closer to vegan than that, I should think."
"The stuff that's pre-digested by civet cats?" He frowned, and I automatically counted the wrinkles. AIs had a slight preference to prime numbers, but this guy's head wrinkled into six slightly uneven furrows.
"Yes, but since the cats eat the coffee cherries, and aren't caged or in any other way coerced into eating them, and everything after that is pretty much manual labour, there's no animals harmed or exploited in the production of the coffee."
He thought about this, and as he did a tiny little tic appeared under his left eye and vibrated for a couple of seconds until he reached up and rubbed it.
"Sounds like it's worth a taste," he said. "You're paying, right?"
"And you're a robot," I said, standing up to go to the counter. He put out a hand to stop me.
"How?" he asked.
"Serial number first," I said. "Confirm it for me."
"XJS6001-10189-5.88," he said, speaking rapidly and so quietly he was nearly whispering. My phone automatically recorded the number and beeped, so I touched the Confirm icon and it came back nearly instantaneously: welder-droid in a factory in New Hampshire. Had an arm, but definitely no face, no feet, and no expensive wool suit.
"Right," I said, knowing that I'd not looked at the phone for long enough for him to think I'd done anything but check the Yes/No display. "You've got servo-motor stiffness that humans just don't show."
"Of course," he said, nodding his head, suddenly slightly jerky. "You did extremely well to spot that. You are, of course, no longer qualified to be a Turing Observer now."
"Of course," I said, contriving an expression of dismay with a hint of happiness behind it. "I'm sorry."
"Don't be," he said, and left as abruptly as he'd arrived.
I looked around the coffee shop and sipped my coffee, and thought some more about him. He was a robot, and he'd lied about the serial number to see how I'd react. He was far too perfect to be human and showed too little interest in coffee crapped out by some kind of cat. Even the most perfect vegan would have had more of an opinion on it than he had.
And I didn't want to be a Turing Observer again. I'd hated having to fail humans, but I'd hated having to pass the AIs as well, because they were changing what it meant to be human. Soon only the AIs would be able to be human enough to pass, and then they'd be free to redefine humanity in their own image. I didn't much look forward to that day.