As the dark came, Jenö told a ghost story. It was a child’s tale, and hardly frightening at all, about a kid who lived on his own in the forest, and who let in any man who knocked and called him son, even the man with the axe in his bag. I watched Charlotte as he told it: her face blank as she listened. I imagined her concentrating like this, at the State Opera in Prague, or studying the life models at Charles University. Had anyone else ever loved her as I loved her? Surely that was an impossibility.

‘Did you know,’ Walter said, taking over from where Jenö had left off, ‘that Charlotte von Stein haunts these woods?’

‘Nonsense,’ said Irmi.

‘It’s true,’ Walter said, ‘she and Goethe used to walk this forest. She was married, but her husband was so often away that she saw as much of Goethe as she liked. They met in the Ilm Park. He fell in love with her on the spot.’

I knew the feeling: Charlotte and Charlotte, me and Goethe, all of us in love by the River Ilm.

‘Charlotte used to read his poetry, and offer him suggestions. He prized her as the best editor he’d ever had. They were great friends. Lovers, maybe. She certainly loved him far more than she loved her husband. None of her four daughters had survived, and she said walking these woods with him was a balm. Goethe couldn’t have been a more sincere, more faithful friend, and he said she was his soul. To read their letters . . . Well, they are so full of affection that you can’t help but feel the force of it.’

Walter cleaned his glasses with a handkerchief, squinting before putting them back on. He caught my eye, and smiled, but went on in a solemn tone: ‘Then, one day, Goethe simply left. He didn’t tell Charlotte where he was going. He wrote to her from Venice. He said he’d be gone a year or two. Charlotte was bereft. How could he have left her here? Without even saying goodbye? His heartlessness was incomprehensible; unthinkable. All that time she roamed these woods, waiting for him to return. That year she wrote an opera about Dido, who cursed Aeneas for leaving her in Carthage, and vowed revenge.

‘Goethe thought of his Italian journey as the happiest of his life, in the land where the lemon trees blossom. And yet Charlotte was here, miserable among the beech trees, while he was in Italy, sighing about lemons. When he returned they became friends again, but it was nothing like how it had been. How can a man be so sensitive to the human condition, and yet be so cruel as to leave her behind, without even saying goodbye?’