It was bitterly cold, but the fog had vanished and the air was sharp and clear as a cut diamond. Rosa shivered as she pulled her cloak tighter around her and tucked her hands a little deeper into her swan-down muff. The sky was a glittering net filled with stars, and wishes, and bright hopes for impossible tomorrows, yet she could feel a soft sadness creeping over her.

She trailed the other guests as they followed the signs erected on the lawn, guiding them round to the back of the house in a swirl of lamplight, like a golden paint-stroke from a magician’s paintbrush. As she walked, Rosa was puzzled by the quiet. She had expected music – perhaps a band or orchestra in full swing, the stamp of feet upon a dance floor, the laughter of couples twirling beneath the stars. Instead there was only a frosty hush, as if the snow had soaked up all sound.

There was not even a golden glow in the sky from lanterns, and lights, and leagues of endless candles. It was as if there weren’t really a pleasure garden here at all. Had it not been for the other guests, Rosa might have wondered whether she’d got the days muddled up and come at the wrong time.

But when they went round the corner, the people in front of her gasped. The East Garden had been transformed into a sparkling fairyland of flowers, and ice, and candles hung in glass jars from the crooked branches of the black apple trees. Their baby lights flickered sweetly in the darkness, casting a ghostly sheen across the blue snow, adding glitter to the frost and smudging smoky shadows into the edges of the garden.

A decorative arch marked the entrance and was covered in dozens of ice roses that threw back the candlelight in speckles and glints of golden confetti. Rosa thought at first that the flowers must be a carved sculpture, but as she approached she saw that they were living blooms. It was possible to make out the fine hairs upon the thorny stems, the lines of the leaves and the delicate stamens within the folds of ruffled petals. There was a scent too, faint but fragrant, of sugared petals, and frosted pollen, and the minty snap of something icy cold. As she watched, a blue-and-silver striped bee suddenly wriggled free from one of the roses and took off, making a lazy trail through the air.

‘Welcome to the winter garden of Half Moon House.’

Rosa turned in the direction of the speaker, a liveried footman carrying a stack of gold-edged pamphlets. He continued to address the group in front of her.