Jelly didn’t need the music. She knew all the melodies as if they inhabited her body. Bernhard followed her easily and his sense of rhythm soon matched hers. She joined in the first Brahms dance; then another. Onkel Jo and the young Brahms had taken the Hungarian melodies from a hotel café band; now Jelly and her unexpected companion were giving them back.

Surprised heads were turning at the tables across the lounge; rustles of silk sounded as the group of sisters rose to move closer to the music. Others followed suit. Floorboards gave the gentlest of creaks as motion spread, rippling like a mystery signal through a shoal of fish. She heard her name conveyed in a half-whisper. A young man slipped out of the room and returned a few moments later with two companions. Jelly closed her eyes and played on. ‘All right?’ she asked Bernhard; but rarely had any pianist looked back at her with such joy.

She recognised people who’d been eating in the restaurant where the waiter had wanted to hide her away, coming in, drawing closer. Dinner jackets, a curl of cigar smoke, the shimmer of a handkerchief in a breast pocket. Sea-green silk, eau de nil, a bare shoulder. Mouths decked with lipstick, scarlet, floral, open in delight. February and the snow was gathering high above them, ready to fall, but in here Jelly could feel sweat gilding her nose.

‘Could you open a window, please?’ she asked the nearest person with a smile. Word went round. A window opened; then another. Theatregoers returning from the performance of Karel Čapek’s Power and Glory next door glanced through, paused at the sight and sound of the musicians, then came in. Her message was changing as it spread through the room. The violinist wanted to open all the windows. The violinist wanted to open all the doors. Jelly d’Arányi, she of the cathedral concerts, the Pilgrimage of Compassion. She wanted to open the doors of the Savoy Hotel and let in the world.

‘And so we will,’ decreed the night manager.

The doors opened on to the Strand. A free concert by Jelly d’Arányi, happening now! Come in out of the snow. Warm yourself by the fire of her presence.

Jelly sidled towards her pianist.

‘What’s going on?’ he said. More and more people were filing into the lounge, many in boots and overcoats, murmurs of surprise and wonderment rumbling among them.

‘I don’t know,’ said Jelly, ‘but I like it. Can you sight-read this Hubay?’

‘I’ll try.’