She cut him off. ‘Don’t let this blight everything. Don’t let it rob you of the things you have a right to be proud of. Do you honestly believe that you’ve never once tried to protect her just because she’s your sister?’
Prabir replied fiercely, ‘If I haven’t, then at least I’m not a slave to my genes.’
Grant’s eyes narrowed. ‘And that matters more to you?’ For a moment Prabir thought he’d lost her, that his words were unforgivable, but then she added drily, ‘At least in a bad enough movie you could turn out to be adopted.’
He said, ‘If that’s your idea of a bad movie, you’ve had a very sheltered life.’
He reached over and stroked her face with the back of his hand. She kept her eyes on his, but said nothing. He’d acted on a barely conscious sense of rightness, half expecting to have his instinct proved utterly mistaken, but she neither encouraged nor rebuffed him. He remembered her watching him, the night they’d arrived; at the time he’d doubted it meant anything at all, but now he felt as if scales had fallen from his eyes.
He bent down and kissed her; they were sitting propped up against the wall of the cabin, it was hard to face her squarely. For a moment she was perfectly still, but then she began to respond. He ran a hand along her arm. The scent of her skin was extraordinary; inhaling it sent warmth flooding through his body. The Canadian girls in high school had smelt as bland and sexless as infants.
He slipped his hand under the back of her shirt and stroked the base of her spine, pulling her towards him, aligning their bodies. He already had an erection; he could feel his pulse where it pressed against her leg. He moved his hand to her breast. He had to fight away any image of where they were heading; he was afraid that if he pictured it he’d come at once. But he didn’t have to think, he didn’t have to plan this: they’d be carried forward by the internal logic of the act.
Grant pulled away suddenly, disentangling herself. ‘This is a bad idea. You know that.’
Prabir was confused. ‘I thought it was what you wanted!’
She opened her mouth as if to deny it, then stopped herself. She said, ‘It doesn’t work like that. I’ve been faithful to Michael for sixteen years. I’ll sit up all night and talk if you want, but I’m not going to fuck you just to make you feel better.’
Prabir stared down at the deck, his face burning with shame.
She said gently, ‘Look, I’m not angry with you. I should have stopped you sooner. Can we just forget about it?’
‘Yeah. Sure.’
He looked up. Grant smiled ruefully and implored him, ‘Don’t make a big deal out of this. We’ve been fine until now, and we can still be fine.’ She rose to her feet. ‘But I think we could both do with some rest.’ She reached down and squeezed his shoulder, then walked into the cabin.
After the lights had gone out, Prabir knelt at the edge of the deck and ejaculated into the water. He rested his head on the guard rail, suddenly cold in the breeze coming in off the sea. The images of her body faded instantly; it was obvious now that he’d never really wanted her. It had been nothing but a temporary confusion between the friendship she’d shown him in the kampung, and the fact that he hadn’t touched Felix for what seemed like a lifetime. It had never occurred to him that he might have lost the knack for celibacy, that after nine years it could take any effort at all to get through a mere three or four weeks.
When he returned to his sleeping bag and closed his eyes, he saw Felix lying beside him, smiling and sated, dark stubble on the golden skin of his throat.
It was not unimaginable any more. Even if he’d had the power to imitate his father in every respect, it would not have brought Radha and Rajendra back to life. And he no longer cared that he couldn’t read between the lines and extract some kind of unspoken blessing from his parents. There had to be an end to
He had to take what he believed was good, and run.
An hour after they’d left Teranesia behind, Grant emerged from the cabin looking bemused.
She said, ‘Strange news from Sao Paulo.’
Prabir grimaced; it sounded like the title of one of Keith’s Country Dada albums. ‘Please tell me we’re not turning back.’
‘We’re not.’ Grant ran her hand through her hair distractedly. ‘I’d say the last thing they need is more data. We seem to have given them rather more than they can cope with.’
‘What do you mean?’
She handed him her notepad. ‘Joaquim Furtado, one of the physicists on the modelling team, has just posted a theory about the protein’s function. The rest of the team have refused to endorse it. I’d be interested to hear what you think.’
Prabir suspected that she was merely being polite, but he skimmed down the page. Furtado’s analysis began with a statement no one could dispute: the discrepancies between the computer model and the test tube experiments proved that there were crucial aspects of the molecule’s behaviour that the simulation was failing to capture. Various refinements to the model had been tried, but so far they’d all failed to improve the situation.
One of the many approximations made by the modellers involved the quantum state of the protein, which was described mathematically in terms of eigenstates for the bonds between atoms: quantum states that possessed definite values for such things as the position of the bond and its vibrational energy. A completely accurate description of the protein would have allowed each of its bonds to exist in a complex superposition of several different eigenstates at once, a state that possessed no definite angles and energies, but only probabilities for a spectrum of different values. Ultimately, the protein as a whole would be seen as a superposition of many possible versions, each with a different shape and a different set of vibrational modes. However, to do this for a molecule with more than ten thousand atoms would have meant keeping track of an astronomical number of combinations of eigenstates, far beyond the capacity of any existing hardware to store, let alone manipulate. So it was routine practice for the most probable eigenstate for each bond to be computed, and from then on taken to be the only one worth considering.
The trouble was, when the Sao Paulo protein was bound to DNA, many of its bonds had two main eigenstates that were equally probable. This left no choice but to select the state of each bond at random: the software tossed several thousand dice, and singled out a particular conformation of the molecule to analyse. And in the first test tube experiments, nature had appeared to be doing virtually the same thing: when the strands of DNA had been copied with random errors, SPP had seemed to be merely amplifying quantum noise when it chose a different base to add to the new strand. But the near-perfect copying of the fruit pigeon chromosome, and the successive intergenerational changes in the DNA from the Suresh butterfly specimens, showed that something far subtler was going on.
The crucial subtlety, Furtado claimed, was that none of the probabilities that controlled the shape of the protein really were precisely equal. One or the other would always be favoured, though the balance was so fine that the choice would depend, with exquisite precision, on the entire quantum state of the strand of DNA to which the protein was bound. Furtado conjectured that SPP was exploiting this sensitivity to count the numbers of various ‘counterfactual cousins’ of the DNA: similar, but non-identical sequences that
Prabir looked up from the notepad. ‘I don’t know what to say. Nobel prize-winning physicists have been throwing rotten fruit at each other for a hundred years over interpretations of quantum mechanics, and as far as I know they’re still at it. Nobody has ever resolved the issues. If Furtado thinks the Many Worlds Interpretation is right, there’s a long list of famous physicists who’d back him up, so who am I to argue? But drawing information from other histories is something different. Even most believers would tell you it could never be done.’