She knew Maria would be in the garden and made her way to the courtyard, stopping a moment to catch her breath when she reached the ground floor. She turned down the corridor to the rear of the house where a door led out into an enclosed garden of grass and paving stones surrounding a low-walled pond. A breeze brushed against her cheek but it hadn’t made any difference to the temperature; it felt as hot as it had been all day. The petal heads on the rose bushes fought the droop of heat valiantly.

Luna walked around the pond to where her sister sat hunched over something. Maria had come into the world less than a year after their father married Lucrezia—a fat, creamy-skinned baby. Everyone said she was perfect, and Luna knew it too. She’d had a covering of blonde curls that stood up from the crown of her head like a quiff and made her seem constantly surprised, which was generally considered to be charming. As soon as she could make a sound, she cooed and gurgled with happy delight. Luna loved her little sister with a pureness she had not thought possible.

Sitting was not easy so Luna perched on the wall beside Maria and watched her sister’s skill—she had a dexterity far beyond her nine years—as she scratched lines into the shell of a hard-boiled egg with one of her sewing needles.

‘Didn’t you hear Mamma calling you in?’ Luna asked, wondering at her sister’s concentration. When she got no response she tried a different tack. ‘Explain to me the pattern you are making.’

‘I’ve made a mess of it,’ Maria said without looking up or stopping. She methodically flicked the tip of the needle at the end of each slow etch. ‘I try to do what Mamma says, and concentrate on the task, but I keep making mistakes.’ She stopped abruptly and crushed the egg into the stone wall.

Luna knew it was the black bile. Maria’s young body had never been in balance and her soul was burdened by an excess of melancholic humour.