“I’d say you’re safe. I don’t think hatred has its own special vibration. In that sense, music is as abstract as maths: it doesn’t make moral distinctions. As long as you follow the score, I don’t imagine there’s any way of detecting it.”

“Follow the score…that’s what I’ve done all my life,” she sighed. We were at the front door now and she put her hand on the doorknob. “Don’t take any notice of me,” she said, “I’ve had a bad day.”

“But the day isn’t over yet,” I said. “Is there anything I can do to improve it?”

She smiled sadly and took the cello from me.

“Oh, you’re such a Latin man,” she murmured, as if that were something she should be wary of. Still, before she shut the door, she allowed me a last glimpse of her blue eyes.

Two weeks passed. Summer was slowly starting, with mild evenings and very long sunsets. On the first Wednesday in May, on my way home from the Institute, I stopped at a cash machine to get money for my rent. I rang Mrs Eagleton’s doorbell and, as I waited, a man came up the winding path to the house. He was tall and took large strides, and he looked preoccupied. I peered at him out of the corner of my eye as he came to a stop beside me. He had a wide, high forehead and small, deep-set eyes, and a noticeable scar on his chin. He must have been in his mid-fifties, but a kind of contained energy in his movements made him seem still young. There was a brief moment of awkwardness as we both waited at the closed door, until he asked, in a deep, melodious Scottish accent, if I had rung the bell. I said I had and rang for a second time. I said perhaps my first ring had been too brief. As I spoke the man gave me a friendly smile and asked if I was Argentinian.

“So you must be Emily’s graduate student,” he said, switching to perfect Spanish with-amusingly-a Buenos Aires accent.