Lady L occasionally attacked her for making a simple error of pronunciation or wrongly conjugating a verb, and once Riccarda sat there with tears pouring down her cheeks while the august professor ignored her distress. She and I would often study together in the evenings, at her kitchen table. Sometimes we would go together to watch Persian films with titles like The Bicycle or The Cow at a cinema in South Kensington with the curious name of Paris Pullman, which was an easy walk away from where she lived in a sprawling ground-floor flat in Barkston Gardens.

Marco called her the mystery woman; we knew she was married, because the teachers always addressed her as Mrs Santini. But it was only later and gradually that I pieced together her private life. She had been a concert pianist – a child performer in her Latin American youth, when she accompanied her Argentinian father, the renowned cellist Armando Gris, on tour; and quite successful in Europe later, until, at thirty-two, she married a Swiss banker, with whom, for years, she moved around in the Middle East and Africa. He didn’t like her to play, except at parties. She had also developed stage fright, and often dreamed that she was performing in her underwear, or that she couldn’t read a score and was improvising. For a while, she had lived in Iran with her husband; she developed an interest in photographing statues, monuments and old buildings there. When he was transferred to Kuwait, she’d moved to London, where, depending on the day of the week, she attended Persian classes as an external student, or studied photography with a master photographer. She had a son of fourteen, who was at boarding school in Switzerland. Though she was autonomous throughout the week, her Saturdays and Sundays were busy: I assumed that either, or both, of the males in her life could turn up or demand her presence at any time, except when she was hidden away from the world in the pied-à-terre in Rome she had inherited from her mother. The more I saw of her, the more she seemed to be caged in glamorous seclusion, like a ruler’s widow: but her yearning to escape her confinement had never left her. I suppose I should say that she was forty-five when we met.