The King's Spy (Thomas Hill Trilogy 1) (29 page)

The king’s summons came on the third morning. A guard escorted Thomas to the hall, where the king waited with his courtiers around him, the Master of the Revels and the Court Painter among them. Just what we need, thought Thomas, dancing and portraits. Enough to frighten away any pikeman. To Thomas’s surprise, Rush was not there.

‘Master Hill, it appears that your skills are needed once more. Another message has been intercepted,’ said the king, waving a paper at him. ‘It was hidden in a sword case, and captured near Reading. With Master Rush away on important business, it has been delivered to me. Kindly tell me what you make of it.’

Thomas took the paper from the king’s outstretched hand. The message was short – only two and a half lines – and written in a hand he did not know. He quickly counted the letters. There were one hundred and thirty-four. No numbers and no spaces. No clues at all. ‘Other than that it is short, your majesty,’ he replied, ‘I can tell you nothing. I shall need time to study it.’

‘Time, Master Hill, is one thing we do not have. The queen will soon leave Oxford, and this message must be decoded before she does. She must
not be put in any danger. How long will you need?’

‘That depends upon the cipher used. If it is the Vigenère square again, I will have to find the keyword. In such a short message, that may be difficult. There may not be any repetitions, and the frequencies of letters are unlikely to be helpful. There are too few of them.’

‘And if it is not the square? What then?’

‘Then I should be able to break it within a day.’

‘In that case, you will attend us here tomorrow morning. We shall expect good progress, Master Hill. Pray remember that you are not a free man, and that of time we have little. If you are not able to advise me of progress when we meet again, we will be forced to consider other options.’

‘I shall do my best, your majesty.’

The king leaned forward and spoke softly. ‘Yes, Master Hill, I have no doubt that you will.’

Thomas managed a tiny bow, followed by a swift retreat. This quiet little man, with his pointed beard, his limp and his stammer, was more threatening than any hectoring bully.

Simon was waiting for him in his room. He was sitting by the window, reading the
Iliad
, a glass of Thomas’s wine beside him. Apart from the habit, he looked for all
the world like a contented teacher of classical literature. ‘Ah, there you are, Thomas,’ he said jovially. ‘An excellent claret. I do hope you don’t mind my helping myself.’

‘The claret I do not mind, Simon. It is your unspeakable cheerfulness at this hour of the day that I find offensive. Especially as I have just come from an uncomfortable meeting with the king.’

‘Uncomfortable?’

‘Most uncomfortable. I am unable to leave the college for any reason, I am still under suspicion of murdering my old friend Abraham Fletcher and betraying secrets to the enemy, I have been deceived by Jane Romilly, and I am now expected by the king to decrypt another message.’

‘A new message? Is it our French friend again?’

‘I do hope not. The king wants it done immediately. He’s reluctant to let the queen leave Oxford without knowing what it says.’

‘Naturally. No wonder your temper is short this morning. And what of Rush?’

‘Not present. Away on the king’s business. Or pretending to be. That’s why the message has come to me.’ He paused. ‘How is Jane?’

‘Tearful. She regrets what she did and believes she has lost you. Has she lost you, Thomas?’

‘I don’t know, Simon. I trusted her, as I trusted you.’

‘Trusted, not trust?’

‘Simon, if Jane has lied to me again, so have you.’

‘We knew you would realize that. It’s exactly why I insisted she tell you the truth. All of it. And she has. Believe me.’

‘I am trying to.’

‘Good. Now, what about this message? Can I be of any assistance?’

Thomas thought for a moment. Trusted or not, a willing listener was always helpful. ‘Perhaps you can. Fill the other glass, and let us examine the problem together.’ He took the message from under his shirt and set it on the table.

XZFMGMAYTDSXPMFMMVNLAJCLAWIMELBTHXFLRYHXWIDQJQJTDDMERT
GCKETPMKEGXIEDUJIECTKOYOJDLNEPLBYEBHBKOTPMTIJLMGLPFQEBYJ
QJTDDQRWPCQKICKBIURLTZOCK

‘As you can see, it’s short. Only one hundred and thirty-six letters.’

‘And no numbers this time. Does that mean no coded words?’

‘Not necessarily, although we shall assume that to begin with.’

‘Is there any significance in the lack of spaces?’

‘I doubt it. It might signify a different sender to the last one, or it might be the same sender disguising himself. There’s no way of telling.’

‘So what now?’

Thomas held the paper up to the light of his window. The paper was good quality and the hand an educated one. He could see no distinguishing marks or hidden symbols. It had been concealed in a sword case, which suggested that the decrypted text would be simple and direct. Senders of hidden messages did not expect them to be discovered, and did not usually bother to obscure their meaning, other than with a cipher. With luck, this one had been encrypted by means of a simple alphabetic substitution cipher or a keyword. They would start with those.

‘Now we look for clues.’

‘The words MAY, LAW and KICK jumped off the page. The first two were too short to be codewords. Thomas tried KICK but knew after the first two letters that it too was merely a coincidence. They noted the repetitions of TDD, CK and QJ, decided that they were too coincidental, and had to accept that there would be no shortcut. To find a keyword or simple shift, they would have to analyse the letter frequencies.

It took them only a few minutes to count the letters
and at first glance the distribution was encouraging. There was a single S and a single V, two each of N and Z, eleven Ts, ten Ms and nine Es. A good mix.’

Concen trating on the high numbers, Thomas set about finding the most common letters, E, A and T, while Simon tried the lowest numbers, looking for the least frequent letters, J, Q, X and Z. That too produced nothing, and serious doubts were creeping into Thomas’s mind. If the sender of this message had used nulls, misspellings or other trickery, the decryption would take longer, and the king would not be happy with longer.

One bottle of claret became two, food came and went, and still they had made no progress. By mid-afternoon neither of them had come up with the slightest sliver of a clue as to the method of encryption. Simon was the first to call a halt. ‘Thomas, I’m not used to this type of work. I’ve been over and over this damnable message and it has made my head ache. Shall we take a stroll?’

Thomas looked up from his page of numbers and letters. ‘Odd, that. Praying used to make my head ache. Come on then, friar. A little air may help.’

With Thomas confined to the college, there was nowhere much to stroll other than round and round the big quadrangle in the middle of which noisy cattle
waited to be milked or eaten. ‘Are you really a Franciscan, Simon?’ asked Thomas suddenly.

‘Now that’s an odd question. Why would you think otherwise?’

‘The words you used about yourself. Pragmatism and humour. Not very friarly words.’

‘Monks may be recluses, friars are not. I choose to live in the same world as you. I find both qualities useful.’

‘And you don’t behave like a man of the church. You travelled to Romsey to fetch me, disguised me as one of your own, pro tected me from Rush and brought Jane to visit me in the abbey.’

‘Were these not Christian actions, Thomas? Except, perhaps, for the last, and that was a simple act of kindness to you both. Even a Franciscan knows worldly love when he sees it. Rest assured, Thomas, I am what I appear.’

‘As you wish.’ They made another circuit of the quadrangle. ‘Now, this accursed message. We’d better break it or I may not be anything much longer. This is what I think. We’ve tried everything I know and achieved nothing. I’m afraid it’s Vigenère again, this time without codewords.’

‘Why would the numbers have been omitted?’ asked Simon.

‘The strength of codes is that they can be quickly decoded by the intended recipient. In the case of the square, they also make the frequency analysis harder by reducing the number of letters in the text. This is a very short message, which in itself is protection against decryption. If the keyword has, say, five letters, there will be no more than twenty-seven letters in each group. Too few to be much use, although I shall of course try.’

‘And do you see Rush behind it?’

‘I do. He’s no fool. He suggested to the king that I show them how the decryption of the last message worked, and he’s realized that, unless the text is short, the length of a keyword can be worked out. And he may have inserted nulls or misspellings, or both, to throw unwelcome hounds off his scent. Why otherwise would the encryption be as it is? If Rush wrote this message, it may well concern the queen, and we must discover its contents.’

‘So a long night of counting letters and looking for vowels, is that it, Thomas?’

‘It is.’

‘I would gladly offer to help, but the queen will expect me for her evening devotions.’

‘Of course. I’m used to working alone.’ They came to the college gate. ‘Now be off with you, and please ask Jane to visit soon.’

‘I shall. Goodbye, Thomas. I’ll offer a prayer for you.’

The long day did indeed turn into a long night. Every effort to pin down just one letter of the keyword had failed, and Thomas was losing heart. Twelve hours of toil had achieved nothing. By the early hours, he had tried everything he could think of, and had even guessed keywords that might have dictated the alphabetic shift. Nothing had worked. Tomorrow’s meeting with the king would not be a pleasant experience, but he had to plead for more time.

The next morning, the king was in no mood for explanations or excuses. ‘So, Master Hill, am I to understand that you have made no progress whatever?’ he asked, impatiently tapping his stick on the floor. Tobias Rush stood at his shoulder.

‘I have made progress by the elimination of simple ciphers, your majesty,’ replied Thomas, trying to keep his voice steady. ‘This message has been encrypted by a very cautious man indeed. He hid it, encrypted it with some complex method, which I am now sure is the Vigenère cipher, and may also have left false trails.’

‘I would be a great deal more pleased if you were able to tell me that you had broken the cipher, as would Master Rush.’

‘Indeed I would, your majesty,’ agreed Rush, with a smirk that the king could not see. ‘As you know, I was unconvinced by Master Hill’s explanation of his previous effort and his lack of progress now reinforces my view. I wonder whether your majesty would be well advised to entrust the message to another, more reliable man. I have someone suitable in mind. Master Hill would not then be needed and could be sent home, or, if your majesty wished, held at your pleasure.’

The king raised an eyebrow. ‘What have you to say to that, Master Hill?’

Thomas knew he had to take care. Rush would have him thrown back into that cell as quick as you like. ‘I am at your majesty’s service. I ask you to believe me when I say that I have made progress, and am confident of success. We are dealing with a very complex cipher, with only one hundred and thirty-six letters to work on, and anyone taking over from me would wish to start again using his own techniques. He would not wish, as I would not, to accept the workings of someone else. That would create more delay, which could be fatal to our cause.’

‘So what is to be done?’

‘I need more time, your majesty. All ciphers can be broken. It just takes time.’

The king hesitated. ‘You have already tried my patience, and I am reluctant to delay the queen’s departure any longer. If you cannot bring me the decrypted message by tomorrow morning, you will be released from your duties. In that case, Master Rush will advise me on what further course of action to take. Good day, Master Hill.’

A stay of execution, thought Thomas, walking back to his room. Damocles’ sword still held by a thread above his head. Twenty-four hours to break the cipher. To work, Thomas, to work.

His room was just as he had left it, except for one thing. His working papers – all but the original message under his shirt – had gone. While he had been with the king, Thomas had had an unwelcome visitor. Another one. A tidy one, but nevertheless un welcome. And there was only one person who could have arranged it, knowing for certain that Thomas would be otherwise engaged. Not that there was the slightest reason to inform the king, or anyone else. Rush would simply accuse Thomas of destroying the papers himself in order to provide an excuse for failing to decrypt the message. And, on reflection, perhaps it was not such a bad thing. An uncluttered table might help unclutter the mind. He still had the message itself, and could, without much difficulty, resume where he had
left off. Rush might even assume that the copy that had been taken was the original, and that Thomas had no other. All the more reason to surprise the repulsive creature.

He started by reworking the distribution arising from a seven-letter keyword. When the first letter threw up impossible combinations, he knew he was wasting his time. Not enough letters, with or without tricks. Unclutter the mind, forget this approach, Thomas, and think of something else.

But what else? How could he break a Vigenère cipher without being able to attack it by frequency analysis? And a Vigenère cipher he was now quite sure it was. Anything else would by now have revealed itself, and it was just what the devious Rush would have done. Find his enemy’s strength and render it useless. A short message, the cipher and tricks. Unbreakable.

But break it he must. He would count each letter distribution separately, starting with a four-letter keyword and working his way up to eight. The chances of its being longer were remote. Too complicated and time-consuming to encrypt and decrypt. If he learned nothing from that, he would have to look for nulls, just as he had before, only this time in the context of the square. He’d need Simon’s prayers, or the meeting next morning with the king would be his last.