I smiled and laid the book aside, for I found it odious and boring. The breeze fanned my face, intoxicating with the scent of the new-cut hay meadows, and I tilted my head back to watch the moving pattern of leaves against the sky. Then, as if my mind had suddenly clicked into a different position, like the gears on a clock, I saw a pattern of moving sky and clouds against the fixed and unmoving leaves. This sudden new quality of vision entranced me, so that I wondered if I could work the change myself. From where I was sitting I could see my grandfather’s prize stallion down in the water meadow below. He was a creature of air and fire, of Arab breeding, scarcely seeming to touch the ground when he flew across the meadow in the sheer joy of living. But he was still now, his head up and his ears pricked forward as if he were listening to something only he could hear. His off fore was lifted slightly, with the tip of the hoof just brushing the ground. I fixed my eyes on him, his solid muscles shivering slightly under the gleaming chestnut coat, the whole, ecstatic shape of him outlined against the soft green of the meadow. I concentrated my mind on the grass that framed him, straining to turn my vision inside out, and, with that almost audible click, it happened again. The stallion became a space, an absence, and the shape of the meadow grass was solid and looming, even menacing in the urgent authority of its presence, its need to be recognised and acknowledged. My heart gave an uncertain jump of excitement, almost of fear, as I gained a first glimpse of the way substance can be transformed into shadow, shadow into substance.

I remember other things about that summer. How I seemed to grow suddenly taller. When I walked and looked about me, I felt as if I had been transformed into some strange creature, like one of the wandering circus players who came sometimes to Coimbra to perform in the streets – fire-eaters and rope dancers and the masked characters from the Italian Commedia dell’Arte: Pantalone, Arlecchino, Pulcinella, and Il Capitano. I was like the man who walked about on stilts, for overnight the ground seemed much further away, so that I had a sense almost of flying, of being no longer in touch with the solid ground beneath my feet.

And I remember one day of scalding heat when I took refuge in the cool stone dairy amongst the dishes where the milk was set so that the cream might settle on the surface and I watched the maids, with their bare arms freckled from the sun, languidly skimming off the cream with shallow ladles, and although they talked and laughed and even sang amongst themselves as they worked, it was as if I had grown deaf, for I could not hear them. I heard the chink of the ladles against the wide pottery bowls and I heard the silken sound of the cream pouring into the jugs for the house and I heard some small bird chirping in a bush of rosemary outside the open door, but I did not hear the girls, whose voices had dwindled to a murmur like a distant stream. And I wished that I could be one of these girls, at their slow and quiet work here in the cool dairy, and that I need never go back to Coimbra and my lessons and the secrecy that surrounded us there.

One day Isabel and I went to pick flowers in the meadow where the stallion grazed. She dared me to ride him, and I did. I have never felt such unity with a horse. We galloped together across the grass, my fingers twisted in the coarse hair of his mane, my skirts hitched up around my hips, and the spicy scent of thyme and the pungent, feline scent of basil, crushed by his great hoofs, rising around me. When at last I flung myself to the ground and kissed his nose by way of thanks, Isabel laughed and held out to me a garland she had made of meadow flowers, and set it on my head like a crown.

Strange, how some memories stay with us, clear and sharp in the mind, while others are forever lost. I can see my sister smiling as she garlanded me with flowers, feel her breath warm on my cheek, as if it had happened this morning, and not in that vanished summer.

It was late July when my father sent word for my mother to bring me back to the town for a few days. Some famous mathematician was visiting the university from Bologna, one of my father’s old teachers, and he wanted to meet me. I do not know what my father had told him, but I was sullen and disobliging when told I must go.

We travelled to Coimbra the next day, leaving Felipe and Isabel with my grandparents, reaching our town house in the evening. My father did not return until I had gone upstairs to bed, where my maid helped me to undress and brushed my thick curls, which I wore long and which were tangled and unkempt after my unruly weeks in the country. I did not see my father until the next morning, when he took me to meet the visitor in the garden of the university.

He was a kindly man, white-bearded, with deep-sunk eyes which gleamed with intelligence.

‘Good morning, Caterina,’ he said formally, leading me by the hand to a bench under an ornamental arch, heavy with the scent of yellow roses.

There he quizzed me on Euclid and Ptolemy, then gave me some problems to solve. As I set about them, using the Moorish methods of handling unknown quantities and laying out what we call ‘equations’, he made approving noises. It seems I solved the problems to his satisfaction, for we moved on to a discussion of the universe, the latest theories of Dee and other mathematicians. It was then I first heard the name of Thomas Harriot, who was later to become my teacher. The Italian spoke also of new discoveries in optics, though my father explained I had not yet made any study of this subject. As the professor spoke, I thought of my strange experiences of perception that summer and wondered whether this new science might somehow explain them.

After he had finished his examination, the Italian laid his hand on my head.

‘You have a good mind, Caterina, and you must take care always to study and nurture your intellect.’ He looked kindly into my eyes, but he sighed and shook his head. ‘’Tis pity you are a girl. It will be a kind of prison for you all your life.’

The Italian dined with us that evening, and I was allowed to sit at table with my elders, which was not usually our practice at a formal dinner. I remember that my hair was elaborately looped with pearls, and I wore my finest gown, its stomacher stiff with embroidery (over which I had laboured long and bitterly the previous winter), sleeves ruched at the shoulders but so tight below I could hardly bend my arms, and a ruff, small but trimmed with delicate lace.

The meal continued for a long time, our visitor and my father reminiscing about days long gone in Bologna, and I think my mother was as weary as I was when at last he left and we climbed the stairs, well past midnight. I was thankful to put on my shift, cool at last after my heavy clothes, which were so uncomfortable in the hot weather, and I lay on my bed with nothing, not even a sheet, over me. I thought the demands of the day and the rich meal would keep me awake, but I fell asleep as soon as I curled up on my side. It must have been three or four hours later when I woke to the pounding on the front door and the frantic barking of our dogs, which set off all the dogs in the neighbourhood, the barking spreading out from our house like the ripples when a stone is dropped into water, till far away the sound faded from hearing.

That was when they came for us.

Chapter Four

The afternoon following the day that Poley took me to Walsingham’s house in Seething Lane, I received a message from Phelippes that I was to join him there and work until curfew. I had spent the morning at the hospital in a state of nervous unease, not knowing whether I would be summoned to the assistant superintendant of the hospital for instructions or reprimand, or whether Poley would appear to drag me off again.