One particular garden in Paris caused quite a stir during the Season. Rosa heard enraptured stories of how it put on spectacular hot-air balloon shows every night, the balloonists returning to the ground with jars full of moonlight. A second garden in Spain boasted a flock of golden songbirds whose beautiful voices freed listeners from the bitter pain of any old grudges they had allowed to fester. Yet another garden had opened around the canals of Venice, and was said to be filled with the mysterious beauty of actual mermaids, whose grey pearls could do such extraordinary things that the people who had experienced them would only speak of the garden in hushed voices.

But Rosa was not intimidated by such talk. Plans for her own garden had progressed well. She had worked diligently on the carousel and – whilst it was not quite the same as the one she had read about in the pop-up book – it was, she felt, still singularly remarkable. It was difficult to imagine that anyone else could have a wonder capable of topping it.

Everything had been ready for some time, but she had deliberately chosen to wait until winter before opening. Her garden needed the cold and darkness to show off the spectacle of its fire and clockwork. After their quarrel, Beatrice had sent Rosa a couple of letters attempting to repair the rift, but since she’d made no mention of withdrawing from the competition, Rosa had refused to respond. For the last eight months Rosa had had no contact with Beatrice at all. She knew she’d been abroad for much of the year and that, scandalously, James Sheppard had accompanied her for some of it.

She felt a sharp sense of hurt about that, which she knew was unfair. Beatrice did not know how she felt about James, nor was the orchid hunter aware that he was helping an adversary of Rosa’s. But still. The one consolation was that so far there had been no garden at Half Moon House, and Rosa nurtured a faint hope that perhaps her old friend had thought better of entering the competition after all. Either that, or perhaps she had failed in whatever it was she’d been trying to bring back.

But then, one morning, a large purple butterfly startled Rosa at the dining-room window whilst she was taking breakfast. For a long moment she stared, dumbstruck. She’d never seen anything like it, and would not have thought such a specimen could exist in England at all. It was easily as big as her palm and looked as if it belonged in a tropical jungle on the other side of the world.

But even more striking than its size was the fact that it carried a creamy envelope attached by a golden string. Rosa leapt up from her seat at once and opened the window. Could it be a message from the Spider Queen?