‘Of course not.’

‘And you will be the very epitome of caution. You should be safe enough with Berden, but when you are on your own, take care. I should not like to lose my best code-breaker.’

He gave me a bleak smile and I flushed. Praise from Phelippes was rare indeed.

‘I will be careful,’ I promised.

Walsingham had given me permission to tell my father and anyone else near to me that I would be carrying despatches to the army in the Low Countries. There was to be no secret about that. What I was not to reveal, however, was the true purpose of the mission, to seek out any treason against Queen and country.

‘The day after tomorrow!’ my father said in dismay, when I told him that evening, after he returned from St Bartholomew’s.

‘Walsingham’s orders,’ I said. ‘I hope there will not be a problem at the hospital. He has promised we will be home before Christmas. That is but four weeks away. And most of the chest infections and influenza strike after December.’

‘We will manage, but are you prepared? Have you warm clothes enough? And where is your own cloak?’

‘Oh, Simon and I have exchanged cloaks for the moment. He also warned me about the weather over there and thought his was warmer.’ It was not, but I had promised not to tell my father about the spying. I had made no such promise before I had told Simon. ‘Is it really so cold in the Low Countries?’

‘Aye, so I have heard. They have more snow than we do in England. Their canals and polders freeze over early in the winter and stay that way until spring. You must take your warmest clothes. Joan!’ He turned to her. ‘You must look out Master Christoval’s winter hose and shirts.’

‘Aye,’ she said grumpily. ‘I heard you. No need to shout. I’ll put them together tomorrow. I’ll be bound his stockings will need mending. They always do.’

‘I’ll grease my heavy boots,’ I said. The prospect of this bitter weather so early in the winter was depressing.

‘The day after tomorrow!’ my father said again suddenly, in the midst of our supper. ‘We are to dine at the Lopez house that day. You cannot offend Ruy Lopez.’

‘I cannot disobey Sir Francis,’ I said. ‘All the arrangements are being made, passports, the horses, a ship. I will go to see Sara tomorrow and beg her pardon. You may still go without me.’

He shook his head, a worried frown on his face, but he did not argue any more. Much as he valued his standing with the more eminent members of our Marrano community, he knew that the orders of the Queen’s Principal Secretary and spymaster must come before all else. For all we knew, the order might have come from Her Majesty herself, though I hardly thought she would have heard of someone as insignificant as Christoval Alvarez.

The next morning early I walked to Wood Street. There were several purchases I wished to make before my journey, but I wanted to call on Sara first. She was pleased to see me, perhaps all the more so because I had scarcely visited once in recent months. I apologised for this and explained how busy we had been, caring for the soldiers from Sluys.

‘Aye,’ she said, leading me into her private parlour. ‘That was a terrible business. I heard how badly the survivors fared.’

‘Better than those who did not survive,’ I said grimly.

‘That is certainly true.’ A maid entered carrying a tray, which she set down on a table and withdrew.

‘I’ve sent for some Hippocras, for it seemed to me the weather was turning even colder today.’ She poured us each a beaker of the steaming spiced wine and passed me a plate of small iced biscuits cut into circles and stars.

‘I have come to apologise also for missing your dinner tomorrow,’ I said. ‘Sir Francis Walsingham is sending me over to the Low Countries on a mission tomorrow morning, so I am afraid my father must come alone.’

‘A mission?’ she said. ‘I thought you worked in the office there, as a code-breaker and translator.’

‘Oh, I do,’ I said hastily, remembering that Sara knew nothing of my other activities for Walsingham last year. ‘It is not exactly a mission. I am to carry a number of despatches and private letters to the Earl of Leicester. You know that he is in command of our forces there.’

She raised her eyebrows. ‘Of course I know that. But why send you? Surely Sir Francis must have a regular courier service.’

‘He does. But the people who work for him are spread all over Europe at present. He needed someone in a hurry.’ I thought how unbelievable this sounded, but Sara was thinking of something else.

‘In my view, it sounds dangerous,’ she said. ‘What if you were to be discovered?’

As one of the very few people who knew my true sex, I realised at once what she meant. Not discovered to be carrying secret documents, but discovered to be a girl.

‘There is no need to worry,’ I said, smiling at her over the rim of my beaker. ‘I am so accustomed to my role as a man that I sometimes forget it myself.’

She shook her head angrily. ‘Do not pretend to me, Caterina. You know how dangerous it will be.’

‘I promise you I will be very careful. But do not speak that name aloud. Do not even think it.’

‘No, of course not.’

‘Tell me, what is happening about the arrangements for Anne’s marriage?’

After that we spoke of other matters, but before I left, she was struck with a sudden thought.

‘Will you be in Amsterdam, Kit?’

‘Perhaps.’ I was cautious, unsure how much I should reveal.

‘I have a cousin there, Ettore Añez, a merchant in precious gems. He lives on Reiger Straat – that’s Heron Street – at the sign of the Leaping Gazelle. He would be glad to see you and hear our news. And if you need a friend, he is there, well known in the merchant community.’

‘I will remember, and if I have the chance I will take him your greetings.’

She kissed me on both cheeks and stood in the doorway as I walked away.

I made my way to Cheapside, where there are shops and street stalls selling every imaginable type of goods. There was a stationer I often frequented, where I bought a supply of quills and a neat travelling ink well so that I could carry ink without the risk of it staining my other possessions. I asked the shopkeeper to fill it with ink and he demonstrated that it did not leak. Tomorrow I would get a packet of paper from Phelippes’s office. I needed all the accoutrements of a conscientious clerk to maintain the fiction of my role. I also bought two lemons. Lemon juice, like milk and urine, makes an excellent invisible ink which can hold a message fitted in between the lines of an innocent letter written in normal ink. Milk is not so easy to come by, certainly when travelling, and urine can be awkward to use in some situations.

At a stall selling cheap but sturdy clothes for workmen I bought a thick scarf and a woollen waistcoat to wear under my doublet. All this talk of the freezing weather in the Low Countries had been causing me some concern. When we had first come to England from Portugal, I had found the winters very hard to bear. I was used to them now, but dreaded anything even colder. I had left Joan mending my thick stockings by the kitchen fire this morning, but I decided to buy an extra pair.

Finally I walked down to Eastcheap, to Jake Winterly’s shop. Bess greeted me excitedly and called to the men to come through from the workroom behind the shop.

‘I’m here just as a customer.’ I was embarrassed by all this welcome. ‘I would like a smaller satchel or a wallet to fit inside this.’ I held out the large satchel in which I regularly carried my physician’s supplies. ‘Something that would fit in the bottom. I’m afraid I can’t wait for it to be made, as I’m going away from London tomorrow.’

They looked amongst their stock and found a wallet about six inches wide and the same deep, but it was about two inches too long to fit across the bottom of my satchel.