Andrew Swanston - The King's Spy

CHAPTER 14

XZFMGMAYTDSXPMFMMVNLAJCLAWIMELABTHXFLRY

HXWIDQJQJTDDMERTGCKETPMKEGXIEDUJIECTKOYOJ D

LNEPLBYEBHBKOTPMTIJLMGLPFQEBYJQJTDDQRWPC

QKICKBIURLTZOCK

One hundred and thirty-six letters, which could well prove Rush responsible for the murder of Abraham and the rape of Jane. Not to mention a traitor and a torturer. Thomas was sure they had not been encrypted by simple substitution, or by a Caesar shift. That left Monsieur Vigenère, whom he had already defeated once. But this time the message was short, there was only one repetition of more than two letters, his analysis of letter frequencies had yielded nothing, and the keyword was neither PARIS, nor LONDON, nor ROME.

Now what? Try every country and every city he could think of? Try random words that came to mind? Or think of something else, some new way of attacking Vigenère? For a long time, Thomas sat and stared at the text, occasionally scribbling words on a sheet of paper. Spain, England, France, Italy, Abraham, Jane. ONE EYE IS BROWN YET THE OTHER IS BLUE. Jane Romilly. Rush, Fayne, Parliament, Pym, Traitor. Romsey, Thomas Hill, Jane. He had no more than twelve hours to decrypt this message, and he had no idea what to do other than try possible keywords. Hardly scientific, or even artistic. Where was Hill’s magic when it was needed?

He wrote out a new square, and started with cities — MADRID, LISBON, ATHENS, VIENNA; then countries — SPAIN, AUSTRIA, ITALY, GREECE. Nothing. He tried a random assortment of words and names — FAIRFAX, MILTON, OXFORD, HONOUR, TRUTH, PIETY, PRAYER. Again, nothing. His head ached.

All through the night, Thomas fought off sleep and kept working on the message. It was futile. By dawn, he was beyond sleep and had nothing left to give. He had failed. The message’s secrets, whatever they were, remained secrets. Rush would escape, and his own fate was in the hands of the king. Best to face it with as much courage and dignity as he could manage. He washed, shaved, put on a clean shirt and waited to be summoned. He heard the guards tramping up the staircase, and rose to open the door. There were two of them, both ill-tempered, both complaining loudly. ‘Backwards and forwards across the yard and up some damned staircase. That’s all we do. We’re soldiers, not servants,’ grumbled one.

‘I’d rather be killing Roundheads,’ said the other.

‘Good morning, gentlemen,’ said Thomas, as they reached the top of the staircase. ‘Is the king ready to see me?’

‘He is, sir,’ replied one, ‘and his majesty is in no mood to wait.’ With a final look around the room, and armed with the message and his copy of the square, Thomas followed the soldiers back down the staircase. They marched around the cattle pen in the middle of the quadrangle, and towards the Deanery. They were still complaining. ‘Up and down, backwards and forwards, forwards and backwards. It’s not proper work for the king’s guards.’

‘It is not. We might as well be messenger boys.’

Backwards and forwards, forwards and backwards. Why had he not thought of that? ‘You silly shit,’ said Montaigne. Before he could give the idea more thought, he was ushered into the receiving room, where the king sat, tapping his stick on the stone floor. Guards were stationed around the room, members of his household behind him. This time there was no sign of Rush. ‘Master Hill. My temper is short. The queen must leave Oxford, and I am tired of hearing that this message has not been decrypted. I trust you bring us better news.’

‘Your majesty, my efforts have failed. I have not been able to decrypt the message.’

The king’s face darkened. ‘In that case, I cannot see that we have any further use for your services, Master Hill. You will be taken to the castle and held there until I have decided what shall be done with you.’

‘Your majesty, although I have not yet broken the cipher, there is one idea that I have not yet had the chance to try. May I have your consent to make one final attempt?’

‘Surely, Master Hill,’ replied the king in a voice that was scarcely more than a whisper, ‘you have had sufficient time by now. We have waited patiently for you to bring us the contents of this message, and we have been disappointed. The queen should already have left Oxford. What grounds are there now for believing that you will break the cipher?’

‘I may not, your majesty. I may fail again. But is it not worth allowing a few minutes more — ten at the most — just in case I am right?’

‘Tell me, pray, how this new idea has suddenly come into your head at the very last minute? Is that not a little strange?’

‘It is, your majesty. I cannot account for it, except that providence can play unexpected games.’

The king hesitated, then beckoned to one of his servants. ‘Fetch paper and ink. We will watch Master Hill at his final attempt.’ The servant scurried off, and soon returned with quills, paper and a pot of ink. Thomas took the message and his square from under his shirt and sat at a small table in the corner. But for the scratching of his quill, the room was silent. Even the king had stopped tapping his stick on the floor. Thomas closed his mind to his audience, and concentrated on the message. Above the first ten letters of the text — XZFMGMAYTD — he wrote out PARIS backwards, twice. Then he referred to the square, and wrote a third line of letters above that. Within a few minutes, he had FROMRUSHTO. From Rush to . Surely this was it. The keyword PARIS one way, and SIRAP the other. Simple and clever. Very nearly too clever for Thomas Hill. Resisting the urge to shout Eureka and claim victory, he continued on across the first line. The stick started tapping again. Thomas tried to ignore it.

The eleventh letter of the text was decrypted as A. The recipient’s name must begin with A. But the next three letters were PYM. A Pym? Why not John Pym or J Pym, or just Pym? Thomas knew the answer as soon as he decrypted the twenty-second letter. It was B. As he had suspected, there were nulls in this message, and it looked as though they occurred at every eleventh letter. That would be quite enough to eliminate any repetitions, and to render frequency analysis useless.

‘I believe we have waited long enough,’ said the king. There was a ripple of assent from the audience.

‘Your majesty,’ replied Thomas, standing up and bowing low, ‘I can inform you with confidence that my idea was correct. I have decrypted enough of the message to be sure that I have the keyword. It will take me ten more minutes to complete the decryption.’

The king stared at him. ‘You are fortunate that I am a patient man, Master Hill. In the full knowledge of the consequences of failure, you may proceed.’

Thomas worked as fast as he dared. Mistakes in decryption, especially using the square, were all too easy. After eight minutes he had:

FROMRUSHTOAPYMQUEENWIBLLLEAVEWITCHINDAYSFORDBRIS TOLENREOUTEEXETERFANDFRANCESGHOULDWEATTHEMPT TOEXECIUTEPLANINBJRISTOLIAWAKITINSTRUCTLIONS

And after nine:

FROM RUSH TO PYM. QUEEN WILL LEAVE WITHIN DAYS FOR BRISTOL EN ROUTE EXETER AND FRANCE. SHOULD WE ATTEMPT TO EXECUTE PLAN IN BRISTOL? I AWAIT INSTRUCTIONS.

That was it. Proof. Rush the traitor, Rush the murderer. ‘Your majesty,’ said Thomas, ‘I ask that you and I are left alone. The contents of this message are so grave that no one but you should know them.’

Another ripple from the courtiers, this time of dissent. The king waved it aside. ‘The guards alone will stay.’ The courtiers trooped out, and the king looked expectantly at Thomas. ‘Well, Master Hill, and what is so grave that I alone should hear it?’

‘This message reveals that the queen will travel to Bristol and Exeter, and then to France.’