The Lost Casebooks of Sherlock Holmes (89 page)

‘And the message? What is being measured?'

‘I have got a little further than the line you have seen.' He picked up the paper on which he had been working, and began to read once more. ‘Belt, nine inches main; six inches upper. Amidships, six inches, five inches, and four inches. Forward, five inches and four inches. Aft, extending sixteen feet above and three feet six inches below the load waterline. Bulkheads four inches, forward and aft. Barbettes, that is to say gun turrets, nine inches and eight inches. Gun shields, nine inches. Conning tower, ten inches forward, two inches aft. Communication tube, four inches and three inches forward. Four-inch battery, three inches. Before I woke you, I was able to identify references to light protective plating of a mere inch over the ammunition magazines.'

‘But what does it amount to?'

‘It amounts, my dear friend, to a complete inventory of the armour plating on our latest Dreadnought battle cruiser, faster than yet as powerful as any battleship, but sacrificing armor for speed. Twenty-eight knots, to be precise. Unless I am much mistaken, this is the top-secret legend of particulars for HMS
Tiger
. All her strengths and weaknesses are here. Von Tirpitz would sell his ears and whiskers for such information. Were I an enemy captain or submarine commander, I should now know where a lucky shot just below the waterline or aft of the funnels and abreast of the magazines would blow a battle cruiser of twenty-eight thousand tons to Kingdom Come.'

If this were true, the Royal Navy had been dealt a near-mortal blow and did not even know it. No longer in a mood to sleep, I sat down in my chair. This secret, revealed to the walls of our curtained sitting room in the small hours of a foggy autumn morning, was surely the most momentous that had ever been uttered there. In the hands of a future enemy, it could lose us a major naval battle in the North Sea or the Atlantic. It might well cost us a war.

3

‘The blindfold game of war,' said Holmes quietly. ‘All Europe seems to be at peace under sunny autumn skies. Yet the four of us are now engaged by the enemy as surely as if ultimatums had expired and ambassadors had been withdrawn. The battle of smoke and mirrors begins.'

A warm morning light filled the sitting room, from which the last odours of a heartily eaten fried breakfast had not quite faded. Holmes had sent his wire to Fisher with strict orders that the First Sea Lord was to travel in mufti and by hansom cab. Fisher from Whitehall and Lord Esher from Windsor had arrived simultaneously, suggesting that they had convened a hasty conference before meeting us. Esher looked relatively composed at what he now heard, but Sir John Fisher's complexion was drained and white as candle wax.

‘What is to be our first step?' His question was directed at Esher, but it was Holmes who intervened.

‘Do nothing, Sir John. Allow the traitor continued access to secret documents and to think himself secure. Let the transmissions continue. Only see to it that the most vulnerable documents are replaced by copies that contain as much false information as possible. Give away only what you think the enemy may know already and what he might gather from public information. Apart from that, feed him falsehoods, if you can. Tirpitz has no reason, presumably, to know that your man in Berlin has discovered what is going on. Here is your chance to lead the grand admiral a dance. It is all you can do. Follow that one gleam of light. A single arrest will leave you in darkness.'

This time it was Sir John Fisher who got up and crossed to the window. With one hand in the palm of the other behind his back, he gazed down at a file of children being brought home from play in the park.

‘We cannot change course,' he said at length. ‘So long as we had five or six of the Dreadnought class of battleship and Tirpitz had none, we were ahead. If I had had my way, we should have followed Lord Nelson's example and Copenhagened the High Seas Fleet and the Kiel Canal, with fifteen thousand Royal Marines ashore, but the king would not have it. Now Tirpitz has his Dreadnoughts—and his submarines. Make no mistake, my dear Holmes, the game has changed. We can outdo him only by faster ships carrying the same armament. That, gentlemen, is the rationale of the Dreadnought battle cruiser, of which we have a dozen and he has none. Speed rather than armor plate is its protection. Last month, two ships of the class,
Inflexible
and
Invincible
, were steamed at full speed, seven thousand miles to the Falklands. There was not the slightest hitch in their water tube boilers or their turbine machinery. They would be upon the enemy before he could know it. But an enemy who had the secrets of their design, particularly areas less endowed with protective armour, would know exactly where to put a torpedo or a shell through these weaker points.'

The First Sea Lord turned from the window.

‘You must not intervene,' Holmes insisted in the same calm voice. ‘Information must continue to flow. The Morse code signals must be allowed to go out as usual. The best you can do for the moment is to let them carry falsified legends of ships' particulars or misleading figures of turbine and boiler performance.'

Fisher pulled a face.

‘It will be difficult. We may cause confusion in our own ranks.'

‘Nevertheless, it must be done,' said Holmes patiently. ‘There is no other way.'

A dozen times in the next few weeks a plain envelope arrived ‘by hand of messenger,' usually a young Royal Navy staff officer in mufti bearing details of the intercepted signals. Once again Sherlock Holmes worked day and night. This time not a sentence, not a phrase, in
Through the looking-glass and what Alice found there
matched the garbled blocks of fourteen letters. Perhaps, as a matter of routine, our enemies had switched to another text as their key. Holmes grew more gloomy as the October days drew in and November took its turn.

‘They cannot suspect anything amiss,' I said, trying to reassure him. ‘After all, their signals are still being sent out.'

He did not seem to be much reassured beyond sighing and saying, ‘It means we are left with trial and error, Watson. Brother Mycroft and the advanced mathematicians are apt to refer to certain numbers so vast that they are “beyond computation.” Such are the odds against us now.'

He sat one afternoon with a dozen transcripts before him. Jackie Fisher was at him every day, insisting that until one more signal was deciphered there was no way of knowing whether our spy had been deceived by the falsified documents.

Presently, Mrs. Hudson brought a tray of tea things and set the silver teapot down beside him on the table. As the good lady went out again, Holmes turned to me and said, ‘This is all wrong. It cannot be done.'

I was shaken by his remark, for it was the only occasion on which I had heard him use such words. Then he paused and corrected himself.

‘It cannot be done in the way that we are doing it now. The key may be in any book in the world or in a single word used over and over. We are being led by a ring in our noses. Our mistake, Watson, is that we are beginning at the beginning, when we should be beginning at the end.'

‘How can we begin at the end? We need the key first to decipher the message.'

He shook his head.

‘We shall never fathom the key. That is what they count upon. At a guess, it would take a length of time approximately equal to the present age of the universe. Let us ignore the key and, instead, try to guess correctly even a small part of the signal sent. We shall try to work backwards from the letters of the encrypted signal to the letters of the code. Once we have part of the code, we may work forward to the rest.'

Having no better suggestion, I let him have his way.

‘However elusive the key to the code, my dear Watson, we may be sure of certain words in the messages sent. Remove their disguise and you have part of the key.'

‘Such as?'

‘Given the events of the recent past, it is inconceivable that ‘
Dreadnought
' should not be among the words in the signals. May I be shot if one block of fourteen letters does not contain that name. The secrets of that class of ship is the prize they seek.'

‘Dreadnought is eleven letters, not fourteen,' I said cautiously.

‘Very well. Let us allow for Teutonic formality. ‘
HMS DREADNOUGHT
' will give us fourteen letters.'

He gathered up the transcripts and we prepared to work through the night. It was a little after two in the morning when we were working on a recent signal. The fourteen grouped letters were still gibberish—
KQSUDIMUUCFSLL
.

‘Once again,' said Holmes patiently, ‘suppose that these letters signal ‘HMS
Dreadnought
,' what will the cipher key be?'

Carefully, he began to trace the sequence back. We had tested hundreds of these groups against the reading ‘
HMS DREADNOUGHT
' in the hope each time that this was their message—but without success. One by one he followed the present string of letters to see whether they might yield a key. Two minutes later we stared at the result. It was a key and a message in one.

‘
DEAR ME, MR HOLMES
'

I felt the shock like a blow to the chest. The thing was impossible, and yet, as we had worked through the night, it now seemed as if our distant and invisible enemies had been thinking our very thoughts for us. We got up and went in silence to our usual arm chairs. After so much work, my despair was all the greater.

‘Well, that is the end of it,' I said miserably. ‘How the devil could they know?'

Holmes knocked his pipe out against the fireplace and refilled it. For a moment he said nothing. Then he lit his pipe and turned to me.

‘I believe they could not know. Therefore, they did not know. If I am right, this is in every sense a lucky shot, a shot in a thousand. It has a ring of heavy Germanic facetiousness. You will recall that several of my adventures, such as they are, lie in the hands of the public, thanks to your gift for romanticized narratives. I should find it remarkable if they were not read by such men as these. This was a phrase of the late Professor Moriarty's and has circulated widely. We must proceed on the assumption that it is pleasantry among our adversaries and no more.'

‘Can we do that?'

He seemed remarkably unruffled.

‘You will observe that several signals were sent after the date of this one. That surely would not have happened had they thought the hunters were on their trail. You will also recall that when our visitors have come here, I have surveyed the street from time to time. I do not think that they were followed or watched. All the same, it may come to that. I think it is as well that we should hold future discussions with Sir John and Lord Esher away from public scrutiny.'

I was far from reassured. On the following afternoon a private room of the Diogenes Club was secured for us by Mycroft Holmes. We had thrown off any pursuers by taking a twopenny bus from Baker Street to Oxford Circus, alighting, then getting on again after the waiting passengers had done so. Anyone following us would have had to get off and on as well. None did.

Furthermore, Sir John Fisher assured us that the Morse code transmissions had continued. Two signals were intercepted in the previous week. Had the signallers believed that their codes had been deciphered and that they themselves were in danger, they would have fled before then. It seemed as if the use of ‘Sherlock Holmes' in their key was, after all, merely a joke among those who thought themselves superior even to the famous detective.

Yet my relief was short-lived, as Sir John spread before us the latest transcripts. I expected the usual groups of fourteen letters. What I saw was quite different.

72-48-03-61-74
|
82-30-42-13-06-53
|
29-71-46-22
|
38-72-49-17
|

The First Sea Lord looked up at us.

‘They have abandoned Morse for a two-digit code. Our monitors now hear two series of short pulses from one to ten. A pause. Two more. Then a long pulse, no doubt to signal the end of a word. It is something entirely new. At any rate, our people have never come across the like of it. What do you say to it now?'

Holmes stretched out his long legs and touched his fingertips together.

‘Never fear, Sir John. I believe you are wrong in supposing this device to be new. Something tells me that it goes back many centuries. Moreover, the fact that the signals are still going out confirms, as you say, that their reference to me was mere whimsy inspired by Watson's turn for romantic fiction. In that, as so often in such matters, it seems I have been proved correct.'

4

Further precautions were taken. There was no more post ‘by hand of officer.' Intercepted signals were to be relayed direct to us from the rooftop mast of Admiralty Arch. Pride of place on his worktable went to an ‘ink-writer' devised by Holmes some years earlier. From a wire aerial it could take down messages in Morse. Rescued from the attic, this contraption worked on an accumulator battery. I saw only a square glass jar filled with sulphuric acid and distilled water. By means I did not comprehend, an endless strip of white paper moved slowly above the inkwell as a message was received. A stylus attached to the mechanism kept pace with the signals of each transmission, drawing dashes or dots in time with it. Holmes assured me that it required only an electric current from the battery to pass through a magnet. A lever would then lift a small ink wheel into contact with the paper.

‘The length of an ink mark depends upon how long the current flows,' he said, not for the first time. ‘Dots or dashes are determined by the duration of the current. By this means, our friends at Admiralty Arch can transmit to us in Morse code. In the case of the new code, however, they will transmit dashes for digits often and dots for single numerals, making up the pairs of numbers that our adversaries now appear to prefer.'