'Oh my,' Mackenzie interrupted, turning to Thomas. 'You would love to know what we're working on, wouldn't you? A cognitive psychologist? We've been forced to completely abandon all the folk psychological assumptions. The old eliminativists were right! None of the traditional categories are adequate—things are much stranger than you can imagine! I mean, take language—oh-ho! We experience nothing but smoke, nothing but smoke!'

Dr Mackenzie, Thomas realized, had a true passion for his work; he simply assumed that Thomas must feel the same. As it happened, this was another common human bias, sometimes called the 'consensus fallacy'.

'Just for example, we've completely isolated the rationalization module in the left hemisphere.'

'Rationalization module…' Sam repeated dubiously. 'Huh?'

'If you shut down the mitigating circuitry,' Mackenzie continued, 'you wouldn't believe the confabulations it generates. Lies, lies, endless lies, each of them completely true as far as the subject is concerned. It's as though each of us has a psychopathic liar built right into our heads! Can you imagine? I mean the evolutionary rationale is plain enough: reproductive success is tied to social status is tied to verbal competition, and so on and so on…' With these last words, he rocked his head from side to side.

'So Ramachandran was wrong?' Thomas asked.

'Ramachandran?' Mackenzie exclaimed. 'Wrong? Please, that's like saying ancient Greek medicine was wrong. "Wrong" is entirely beside the point, at least at this juncture. We've moved so far beyond that, so—'

He suddenly stopped, his open-eyed enthusiasm narrowing into something at once shrewd and sly. He didn't laugh so much as snicker.

'You should be commended,' he said to Sam while waving a finger. 'Bringing another academic with you. You knew that I would be more likely to open up if I could talk shop, now didn't you? I imagine we eggheads are rather predictably vain, hmm?'

He stubbed out his cigarette with his thumb.

Sam smiled and shook her head. She seemed to make a point of avoiding Thomas's gaze.

Of course, Thomas thought. Why else would she bring him? For his legendary powers of observation?

He knew the resentment he felt was more a function of the past couple of days than anything else. Hadn't she told him to read between the lines? More importantly, didn't she have an obligation to use every means at her disposal to prevent another Cynthia Powski or Peter Halasz? Coddling Thomas wouldn't be high on her list of priorities simply because it couldn't be.

'Tell me,' Sam asked in a queer voice, 'did you ever operate on Neil, Dr Mackenzie?' It was a question that only seemed obvious after she had asked it. Something had to explain Neil's turn to the unthinkable.

Things were moving too quickly.

'Never,' Mackenzie said. 'Why do you ask?'

Thomas stared at him. 'That's the answer you have to give, isn't it?'