Gessen blinked, and the vision was gone. Across the years Sophie had lived on in his imagination as a young woman, though she’d be nearly sixty now. Married, surely, perhaps a grandmother. A wave of regret passed over him like a fog. How young he’d been, how delirious with heartache. Begging her to run away with him, to Canada or America or New Zealand. Anywhere they could start a new life, far from the curse of history.

He should have known that no matter where he turned, there was no escaping the poisonous legacy in his blood. After he’d smashed their dreams to bits, with no explanation for his behaviour, her parents had whisked a heartbroken Sophie away to their country house in Normandy. When she returned to the university in the autumn, thin and lifeless, she met with him once at a nearby cafe, her speech wooden, her eyes flat. He refused to tell her the real reason he’d broken their engagement, having vowed to tell no one about his past. But he couldn’t bear the idea of her believing he was a cad. So he told her a watered-down version of the truth, clasping her hand as he whispered the vile story in her ear. She’d said it didn’t matter to her, that love conquered all. But that wasn’t the point. It mattered to him, and after his wrenching split from Sophie, he’d made a solemn vow to never marry, to never have children. He would be the end of the line.

* * *

By the time Gessen reached his friend’s office, he was a few minutes late, and a student with scraggly hair and a wild look in his eye was just coming through the door. The boy could have been Gessen’s twin, forty years ago, his mind teeming, the thirst for knowledge unquenchable. He knocked and pushed open the door.

‘Anton.’ Bertrand sprang from behind his desk and kissed Gessen noisily on both cheeks. ‘It’s been too long.’

‘Indeed, it has.’ Bertrand had scarcely changed, though. Still thin as a wire, and vibrant as ever. Only the greying hair at his temples betrayed his age.

Bertrand moved a stack of papers from a chair. ‘Please have a seat. I just need to send a couple of emails.’ He removed his glasses and rubbed his eyes. ‘Wretched admin, I’ll never get used to it.’

Gessen scanned the bookshelf while he waited. How different his life would have turned out if he’d stuck with his youthful plan to study philosophy and mathematics instead of switching to medicine. Even now, he kept a much-thumbed edition of Marcus Aurelius’s Meditations in the top drawer of his desk. Often turning to it after a difficult day or a particularly trying session with a patient.