The rural Norfolk accent, it seemed then, was well adapted to a special kind of pleading. In such tones the tenantry might once have begged their manorial lord for lower rents in hard times. ‘I was going to finish this coffee, see, get dressed, tidy up and leave. I was going to double-lock the door from the outside like I was told and put the key through the letterbox. If you hadn’t come back early there wouldn’t have…’

‘I said, what are you doing in my house?’

Using his palms again in a gesture of empty-handed frankness, Aldous said, ‘I had dinner with Patrice and I stayed the night. Look, Professor Beard, may I be frank?’

He paused, as if he really did expect an answer. When he did not get one, he continued, ‘We both value rationality. We’ve made careers out of it. So let’s not be swept up into responses that are no longer appropriate to the situation. We both know that your marriage is over. Technically, you and Patrice are man and wife, but you’re not even on speaking terms and haven’t been for ages, and here you are, getting ready to play the injured party, the furious husband catching his wife’s lover red-handed, when in fact you’re probably thinking of moving out anyway. That’s Patrice’s impression, and it’s certainly her wish.’

Beard waited for more.

‘What I mean to say, Professor Beard – I wish you’d let me call you Michael – is that we could skip all the anger and heartache, we could be efficient about this, and we could even be friends.’

‘I see.’ The question he then put to Aldous came without forethought, and as he asked it, he thought it might perform useful mischief, or at the very least give him a moment to think. ‘And what about Rodney Tarpin? What’s happened to him?’

Aldous gave a good impression of a man pretending to be unfazed. Slowly, he retied once more the belt of Beard’s dressing gown. ‘I’m not afraid of Tarpin. And I’ve recorded two of his phone calls, and a postcard he wrote is now with the police. The man’s a maniac, but at least he doesn’t hide it.’

Beard said, ‘He hit Patrice.’

‘That was grotesque,’ the young man cried out, seeing a common cause to bind the professor to him. ‘How could this guy do a thing like that to such a beautiful woman?’

‘And he attacked me. Hit me in the face.’

‘He should be in prison.’

‘At least now he’ll be on your case, not mine. Are the police offering you protection?’

‘Well, you know, they said they’re rather busy at the moment.’

The urge to punish gave Beard a warm glow that was not unlike love. He said, ‘I suppose he intends to kill you. I’d carry a knife if I were you, not that I care either way what happens to you.’

Despite Beard’s efforts, Aldous did not appear intimidated by Tarpin. He said simply, ‘He doesn’t frighten me, Professor Beard.’

‘And I suppose Patrice would have told him where you work – I mean, where you used to work.’

Instantly, the young man’s cool drained away. He was the supplicant once more, a man with his job on the line.

‘Oh now look, Professor Beard. You’re taking this too far. Let’s go back to the central point. Rationality…’

‘Deeply irrational,’ Beard said, ‘to make love to the boss’s wife.’

‘Honestly, it goes deeper than that. I’ve been stupid, I know I’ve got a lot to learn. But I’m talking about, about a substratum of powerful logic…’

Beard laughed out loud. Substratum! This was like watching a chess player fight his way out of an approaching checkmate. He could remember no particular occasion, but he knew he had been in such situations himself, probably in front of an outraged wife, just when she had blown his last excuse and then, brilliantly, on a surge, he had produced a sleight of mind, a knight’s move in the eleventh dimension, a dazzling projection upwards from the flat-world of the conventional game. Yes, he liked a substratum of powerful logic. He listened.

Aldous spoke breathlessly. ‘Three weeks ago I overheard you saying to one of our group that you believed that apart from general relativity, the Dirac Equation was the most beautiful artefact our civilisation had ever produced. I disagree. You do yourself a disservice. There’s nothing like the Conflation, nothing like this elaboration of the photovoltaics – nothing more elegant, nothing truer, Professor Beard. Everyone everywhere reveres it. But no one has thought it through from the angle of applied science, and the crisis in climate change. And I have, I’ve seen the potential of your work in relation to photosynthesis. The fact is, no one understands in detail how plants work, though they pretend they do. No one really understands how photons are converted to chemical energy so efficiently. Classical physics can’t explain it. This talk of electron transfer is nonsense, it doesn’t add up. How your average leaf transfers energy from one molecular system to another is nothing short of a miracle. But this is the point – the Conflation opens it right up. Quantum coherence is key to the efficiency, you see, with the system sampling all the energy pathways all at once. And the way nanotechnology is heading, we could copy this with the right materials, and then crack water cheaply, and store hydrogen on a domestic or industrial scale. Beautiful! But I’m nothing, I’m no one. I want to show you my ideas, and when you’ve looked at them, I know you’ll go for it. People will listen to you. Quantum coherence in photosynthesis is nothing new, but now we know where to look and what to look at. You could steer this research, you could get a prototype funded. It’s too important to let go, it’s our future, the whole world’s future that’s at stake, and that’s why we can’t afford to be enemies.’

Beard had heard rather too much recently of this whole-world talk. He had never been well disposed to biology enlisting quantum mechanics to its cause. And he had an irrational prejudice against physicists who defected to biology, Schroedinger, Crick and the like, who believed that their brilliant reductionism would carry all before them. In fact, greenery in general – gardening, country rambles, protest movements, photosynthesis, salads – was not to his taste.

‘How long have you been fucking my wife?’

Aldous sighed, and seemed about to object. Then his shoulders sagged and he resigned himself. ‘About a month after I first met her.’

‘After I introduced you.’

‘That’s it, Professor. You were away for the night, Birmingham or Manchester. I called in on my way home to see if there was anything Patrice needed…’

‘And there was.’

Again, the wheedling of the rural tenant. ‘Honest, Professor Beard. I had no designs on your wife. She’s way out of my league. I don’t even have a league. She invited me in, then she asked me to stay to dinner – and that was how it began. Later on she told me how it was all over between you, and I sort of persuaded myself that you um…’

‘Wouldn’t mind?’

He knew it already, but it angered Beard, or worse, it pained him, to hear for the second time from Patrice by way of Aldous that she thought the marriage was over. Since the late summer of last year, she had been seeing Aldous, not Tarpin. Or possibly both. The goofy post-doc turned up on her doorstep one August evening and she grabbed another chance to punish her husband.

‘Has anyone ever told you how naïve you are, Aldous?’

The young man seized on the word with joy. ‘I am naïve, Professor Beard! I do science and nothing else. I’m naïve because I don’t meet people, I don’t go out. I go home and work in the studio in my uncle’s garden, often through till dawn. That’s how I’ve always been. But my work is at your disposal. I’ve been making a file for you. For you and no one else. Please say you’ll read it. This is so important.’

Until then the two men had faced each other over a distance of several feet, Aldous standing close to the sofa, with arms clasped in front of him, as if to defend himself against a possible fate or to prevent Beard’s dressing gown from swinging open. Beard began to back away. He was tired of listening to Aldous, he wanted to be alone.