‘In other words,’ said Fisher quickly, ‘you tell us that the code cannot be broken.’
‘I did not say that. It is necessary to know or deduce what text is being used as the key.’
‘But if that text may lie anywhere, in thousands of books and millions of pages, in dozens of languages, the code cannot be broken. Surely that is what it amounts to? Our own people are only able to say that the same groups of letters are sometimes repeated. As you describe it, these may be repetitions of the same words or differing words that appear in the same letters by chance.’
Holmes shrugged.
‘A code may be broken in only two ways,’ he said patiently. ‘It may be possible to penetrate it a little, at least sufficiently to deduce the principle of its construction by internal evidence. More likely, it must be a matter of trial and error. The code-breakers of His Majesty’s Admiralty have tried and it seems they have erred. It remains to be seen whether I shall do better. I have the advantage, at least, of recognising what sort of code it appears to be.’
It need hardly be said that as I sat there I felt increasingly uncomfortable in the final stages of this encounter. Once or twice I caught the exasperation in glances between Admiral Fisher and Lord Esher. Yet, as in his dealings with Scotland Yard, Sherlock Holmes hardly bothered to disguise his belief that incompetence at the Admiralty had caused the predicament our visitors now found themselves in. This was to put a considerable strain on his friendship with the First Sea Lord. Yet Sir John Fisher was realist enough to know that Holmes was the one man in England who might help him. The transcripts of the intercepted signals must remain where they were—on the shabby worktable in our Baker Street rooms.
For three days Sherlock Holmes scarcely moved from that stained table on which the transcripts were laid. He worked in his purple dressing gown and, for all I know, his pajamas underneath. From first to last he went at his task in a silence that almost forbade anyone in the room to move or breathe. His efforts were broken only by the sound of another sheet of crumpled foolscap hitting or missing the wicker of the wastepaper basket. He looked up, without expression but with evident reproof, every time I tried to turn a page of the
Morning Post
without rustling the paper. I was so obviously a hindrance that I thought it best to leave him to himself. I went for walks nearby in Regent’s Park, where the first yellowed leaves blew and scuffled about the broad avenues of trees. I lunched at my club each day, where at least I could be sure of conversation. Finally I dined there, alone.
Coming back to our rooms as the evening mist of an October night began to gather, I found no welcome fire dancing in the grate. Mrs. Hudson’s timid housemaid had been told not to interrupt ‘the gentleman’ by laying one. No meals were set out on our dining table. Holmes picked at the food like a gypsy from a tray beside his writing pad. He took little nourishment, unless shag tobacco could be counted as such. On the first day he went to bed very late. On the second, as I came into the unaired room at breakfast time, it was plain that he had not moved from his writing chair all night. By any description, he looked white and haggard, like a man who has lost a stone in weight.
‘This really will not do, old fellow,’ I said gently. ‘You will crock yourself up. That will be the end of it. What good will that do?’
He glowered and said nothing. I ate my bacon and eggs, trying not to clink the cutlery. The rustle of butter or marmalade being spread on toast seemed unthinkable. All that day he might as well have been in a trance for what I could get out of him. He sat at the blotter with a few books at his side and covered page after page with scrawled figures, letters, calculations, variations of words in half a dozen languages. Once again, only the light crunch of discarded paper aimed at the basket broke his absolute concentration. He glared at the work before him.
It was just as I was going to bed that I noticed a sudden brightening in his face, shattered though he looked. He glanced up from the folio page before him.
‘Before you turn in, Watson, have the goodness to hand me the third book on the right from the second shelf down.’
I took down a slim red volume, lettered in gilt, its cover tarnished somewhat by frequent reading or reference. My only interest was in going to bed and I did not bother to read the title. I noticed, as he opened it, that the flyleaf bore a neat but faded inscription. ‘To Mr. Sherlock Holmes with the author’s best wishes and sincere thanks.’ I thought nothing of this. There were a few dozen volumes on our shelves presented to him by their grateful authors, whom he had helped out of one fix or another. He peered into its pages, his sharp features contracted in a frown. There was no sound now but the hiss of the white gas lamp that illuminated the table.
At last I said quietly, ‘I beg you to put away these things until tomorrow and get some sleep. This cannot go on without detriment to your health or your concentration and ruin to your eyesight.’
‘Yes, yes,’ he said impatiently, ‘good night.’ After that I might as well not have been in the room.
Though I had taken no part in his day’s labours, I fell asleep at once. The next thing I knew, my shoulder was being tugged violently. I sensed that this had been going on for some time in an effort to rouse me.
‘Watson!’ I saw that his features were alive with excitement; even the sleepless pallor had gone. ‘Get up! I need your immediate assistance. I believe I have it, but you must help me.’
‘Holmes, it is pitch dark. What time is it?’
‘A little before four o’clock. I must have your help in this, old fellow. I need you to listen and tell me whether I am right.’
From the comfortable darkness of my bed I moved slowly downstairs to the tobacco-fogged gaslight of the sitting room. I could not see how on earth he had broken such a code as he described. As I entered the room, Holmes threw down on his table the book I had handed him before going to bed. I picked it up and glanced at the title.
Through the Looking-Glass and what Alice found there
.
‘I deserve to be shot,’ he said triumphantly. ‘Where else should the answer to a looking-glass code be, except in Alice?’
By his chair lay the graph-paper grid of the alphabet that he had drawn up for our visitors. Beside it was a sheet of paper with a single line of writing at the top. He handed it to me with the grid, so that I could follow him. He was as close to exultation as I had ever known him.
‘Put these two together, my dear fellow, and that is the answer. At least in this case.’
I looked at the grid. It was, after all, nothing but the letters of the alphabet written horizontally across the top and vertically down the righthand side, the squares filled in accordingly. Then I studied the first line of the coded message he had been working on. It was in the familiar blocks of fourteen letters each.
PRPMUQAKENUJQR BNAVQPNVABTLLZ TQSLLAMCZSLKWG
JPSOOSLBYPYVCK WGJHXHYABCDHSF
I could make absolutely nothing of this gibberish, nor could I see what help was required. In short, I was not a little irritated at having been woken from sleep to be confronted by it.
‘You may see something in it,’ I said wearily, ‘but I do not. There is a sequence of
A
,
B
,
C
,
D
toward the end, and that is about all.’
He took up the children’s storybook and read aloud the first lines.
‘One thing was certain, that the
white
kitten had had nothing to do with it—it was the black kitten’s fault entirely.’
‘Holmes! It is past four in the morning. Whatever this nonsense about kittens may be, tell me and let us have done with it. I should like to go back to bed!’
He pushed another sheet of paper across the table. In this case, he had written three entries across it, one beneath the other, seventy letters in each case.
As I reached the third of these questions, I knew at once that there would no more sleep for either of us that night.
‘I deserve to be shot,’ he repeated happily. ‘Where else should one find the key to a looking-glass code but in that supreme authority—the work of the Reverend Charles Lutwidge Dodgson, known to the world as Lewis Carroll? I was prepared to try the beginning of every paragraph against every signal in these transcriptions. It is not a long book, little more than a hundred pages, but it would have taken us a week or more. Yet sooner or later there is always a stroke of luck in these matters. One does not count upon it, yet one expects it. The key to the cipher in the fifth signal was in the opening lines of the story! How crass I have been! Yet it is all the fault of these Admiralty people and their invariable knack of missing the point.’
‘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.
‘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.