Sherlock Holmes was proved correct in almost every particular. By the following Tuesday the Admiralty spy was revealed as a young man by the name of Preston, a naval draftsman. Those who knew him called him diligent, solitary, a man of impeccable moral character and strict conscience but with few friends. He lived in a modest house in a South London street where he nursed an invalid sister.
Only a search in the Criminal Record Office files revealed that Preston’s brother-in-law, an attorney’s clerk married to this invalid sister, had sought her cure by plunging heavily into the stock market with money borrowed from the firm’s client account. As usual, he had hoped to replace the ‘loan’ and take the profits it had made for him. As is often the case, his desperate investments had failed him. When he went to gaol, his wife who was Preston’s sister had taken poison. However, she misjudged the dose. The poison did not kill her but left the invalid now crippled and imbecile. Preston had cared for her thereafter. Whether her tragedy bred in him some hatred of his nation or of mankind in general, both of whom had turned their backs upon her and driven the husband and the brother to their respective crimes, who can say?
Under the authority of Superintendent Swain and the Special Branch, the railway police at Charing Cross were enlisted. With their assistance and the authority of the Home Secretary, the attaché case was removed from the cloakroom once it had been deposited on the following Tuesday morning. It contained the instructions, as Holmes had guessed, and the banknotes, as I had suggested. They were £5 notes and the banks have a habit of listing the names to whom they are issued. One had been in a German Embassy draft, while the other had circulated in Germany itself. Within an hour the case was returned to await collection.
Now the blindfold war took a new form. Every Tuesday the attaché case was opened and the list of information required by Dr. Gross or his masters was copied. For the next two days, however, in Room 40 of the Admiralty Building, two draftsmen drew up bogus inventories and plans, details of manoeuvres and gunnery, signals and mobilisation. It was these that Preston was allowed to purloin and that sowed error in the finely worked espionage of our adversaries. Ranges were understated, locations of shore batteries revised, movements and manoeuvres misreported. The armor belt diagrams of our warships were sometimes thickened or extended, sometimes diminished in extent. The High Seas Fleet of Admiral von Tirpitz, which had previously been trained to destroy a precise target, would now shoot at random—or, worse still, in error.
Sherlock Holmes was a frequent visitor to the famous Room 40 of the Admiralty cryptographers during the war that was to come. Yet his greatest service to the nation’s cause was performed before a shot had been fired. Thanks to my friend’s machinations, as the last glorious summer of peace darkened across the continent, Dr. Gross was no longer to be seen at the Charing Cross Hotel. The Great Northern Hotel was his lodging and the railway termini at Kings Cross and Liverpool Street became his promenade. As for his confederates, the Special Branch acted on advice it did not entirely understand and paid out still more rope for the spies to hang themselves.
At the Admiralty, a secret signal was decided upon. It was to be broadcast to all ships of the Royal Navy as soon as a state of war with the German Empire and its allies was declared. That signal was to be ‘England Expects.’ Upon receiving it, ships’ captains would open their secret orders, discover their meaning, and act accordingly in the war of which they were now informed. Yet this signal was not so great a secret that Preston could not get his hands on it. During the last weeks of peace it was encoded by Dr. Gross, transmitted by Karl Henschel, and filed by the Senior Intelligence Officer of the German Ministry of Marine in the Wilhelmstrasse.
The coded signals from Henschel, received by a destroyer of the High Seas Fleet riding an oily swell somewhere off the Thames estuary, continued to carry information on Royal Navy gunnery and ship design. Increasingly these reports were supplemented by reports direct from Dr. Gross. From personal observation the elderly scholar was gathering details of mobilisation and troop movements as the prospect of war drew nearer. Trains from Liverpool Street were carrying Royal Marines to Harwich and Hull, hardly convenient for a campaign in France but essential for an attack upon the North Sea coastline of Germany. Fort Codrington, near Felixstowe and the eastern coast, had become their transit camp. The Fifth and Seventh Destroyer Flotillas were seen off the Wash, moored as if to escort troop transports.
Three weeks before the day on which that most dreadful of all wars began, Dr. Gross was able to inform his masters that the British Admiralty had placed an immediate order with the Stationery Office for 1,200 copies of charts and land maps covering the Danish west coast of Jutland from the Skagerrak at the northern tip to the Frisian Islands and the German frontier in the south. It seemed that Sir John Fisher was to get his wish to ‘Copenhagen’ the enemy and seize the Kiel Canal, perhaps without declaration of war.
Though the landing would be on their territory, there was little doubt which side the Danes would support. They had lost their provinces of Schleswig and Holstein to Germany in the war of 1863 and smarted to recover them. If the Royal Navy put 15,000 Marines ashore on friendly Jutland, these troops would be scarcely a hundred miles from the Kiel Canal, and thus poised to sever Germany’s link between her Baltic and North Sea coasts. Such a spearhead would become a dagger pointed at the heart of Prussia and even at Berlin itself. Indeed, it would be a dagger at Germany’s back as she faced France and Britain on her Western Front.
On the last night of peace in August 1914, as the minutes passed and Berlin ignored each ultimatum from London and Paris to withdraw its invading army from Belgium or else face war, Holmes and I were at Scotland Yard. Neither Preston nor Dr. Gross had been arrested, though both were closely watched. Karl Henschel sat before us, for he alone had been detained and his confederates knew nothing. In the green-walled office above the Thames, with its wooden cupboards, bare table, and hat rack, Alfred Swain interviewed the young man while Holmes and I sat to one side. Henschel seemed indifferent to his fate.
‘I did nothing unlawful,’ he said repeatedly. ‘I was given signals to send and I sent them. Why should I not? I could not tell what was in them. I did not know and it was never explained to me.’
‘Listen to me carefully,’ said Superintendent Swain, leaning forward across the table towards the young man like a true adviser.
‘By your own choice, you became a British subject. Now, it appears, it would have been far better for you to have remained a German. As an alien, you could not commit treason against the King of England.’
‘It was not treason! To send messages!’
‘Please believe me, if war comes, you will be tried for treason as a British citizen. That you will be found guilty is a certainty upon such evidence. Three weeks later you will be taken from your cell at eight o’clock in the morning, a rope will be put round your neck, and you will hang by it until you are dead. No one will notice your death among so many, and no one will care, least of all your paymasters in Berlin. To them you are no more than their post boy.’
‘No one has ever been hanged in England for such a thing as I have done!’
‘Quite right,’ said Swain encouragingly. ‘If you were sentenced this minute, it would be for a breach of the Official Secrets Act. You would probably go to prison for four or five years. I daresay you would be released after three.’
‘Well, then?’
‘Once war begins, what you have done will not be regarded as a breach of Official Secrets but as treachery under the Defence of the Realm Act. For that you will be hanged. The ultimatum is running out for you, Mr. Henshaw, as surely as for your masters in Berlin.’
‘My true name is Henschel, not Henshaw!’
‘Alas,’ said Swain, shaking his head, ‘no. You may wish it was so but it cannot be. You changed it of your own free will, as you became an Englishman of your own free will. And so you will be hanged as Charles Henshaw, the English traitor. If you nourished dreams of being a hero, you may safely forget them. You will have no memorial in your own land. If you are truly fortunate, you will be shot rather than hanged, tied into a kitchen chair on the rifle range of the Tower of London. And that, Mr. Henshaw, is all that you have to look forward to in this world.’
I do not know why but this, of all things, broke his nerve. He trembled and he could not speak. He was, after all, a petty figure in the conspiracy—an impoverished teacher of languages, who now found himself terrifyingly out of his depth. Sherlock Holmes intervened, for all the world as if he were ‘prisoner’s friend,’ as they call it at courts-martial.
‘It will be too late once war has been declared, Herr Henschel. It is neck or nothing for you—here and now. You had best decide at once between prison and the hangman. Indeed, you may yet decide between prison and freedom, but you had best be quick about it.’ Henschel could not reply until he had taken a drink from his glass of water.
‘How can I choose? What is done is done.’ Holmes shrugged.
‘By continuing to do what you have done for several years. Transmit the signals that are given you to transmit. They will mean nothing to you, as you say, but they may save both your life and your liberty. The choice is yours. Life or death. Captivity or freedom.’
The choice, of course, was nothing less than betrayal of his paymasters, and I do not know who had given Holmes the authority to suggest it—possibly Alfred Swain himself. Henschel had a certain value. I am no expert, but I have heard that those who are experienced listeners can identify the very finger of the operator on the Morse code button! How long such a deception might be kept up, I could not tell. Yet every transmission that put the Germans in error was worth its weight in gold. At that moment the great bell of Big Ben, on its parliamentary tower, began to strike eight in the evening. The tolling was close to us and the reverberations long, loud enough to interrupt conversation. It came like a funeral knell for Karl Henschel. If he was not broken already, this broke him. He looked down at his hands in his lap and said:
‘Tell me what to do.’
There was a sudden relief in the room and we breathed more easily, for it is a terrible thing to send a young man to his death in such a way. Holmes crossed to the window and opened it a little for air in the warm August evening.
‘You may demonstrate your expertise for us,’ he said coolly. Though it sounded casual enough, this was what he had been working for.
That night, even before the ultimatum to Germany expired, Henschel tapped out a brief message, repeated several times. I swear that he thought it a mere demonstration and had no idea that it was transmitted through the darkness to his friends in Berlin. Though it was encoded, I read the cipher and saw ‘
ENGLAND EXPECTS
.’
Six weeks earlier, among the falsehoods passed off on Preston and Dr. Gross, this had been the masterstroke of Sherlock Holmes. Admiral von Tirpitz’s intelligence officers had been informed by their spies, who knew no better, that ‘England Expects’ was the signal for launching Sir John Fisher’s ‘Copenhagen,’ the attack on Kiel by way of an invasion of Jutland with 15,000 Royal Marines. Now, on the third floor of Scotland Yard, above the Thames and the street lights of the Embankment, Karl Henschel tapped out that message. Far worse for Grand Admiral Tirpitz and the Kaiser’s High Seas Fleet, the same message was echoed openly in a few hours time when war was declared and it was broadcast to the entire Royal Navy. Ships’ captains opened their sealed orders and read its true meaning—merely that war had begun. Yet to those who listened in Berlin, it seemed that the air was alive with immediate orders to launch or support ‘Copenhagen’ and the seizure of the Kiel Canal.
In the circumstances, what followed is scarcely surprising. It is a matter of history that not a single Royal Marine landed on Danish soil. Most of the ‘Marines’ reported by Dr. Gross at Liverpool Street station were mere barrack-duty veterans dressed for the part on their train journey to the East Coast ports, to give the impression of an army on the move. The destroyers seen on the horizon were ships that passed in the night. It is also a matter of history that Helmuth von Moltke kept back from the Western Front 20,000 of his best troops in Schleswig-Holstein to protect Germany’s Danish flank from this mythical attack. A month later, for want of those 20,000 troops at the Battle of the Marne, the great German advance on the Western Front was halted and beaten into retreat only twenty miles from Paris.
‘Charles Henshaw’ tapped out the signals given him for the rest of that great war. For how long those who listened believed him it is impossible to say. Dr. Gross was briefly interned and then allowed to live at liberty in Oxford. Outrageous though this might seem, Sherlock Holmes insisted that it was the best policy. Preston, the spy in the Admiralty, was suddenly alone and without understanding why. He knew only that the instructions and the money that had awaited him every week at Charing Cross cloakroom ceased to appear from the moment of the war’s beginning. He might have inquired of Dr. Gross or Karl Henschel, but, thanks to the ingenuity of the German espionage system, he did not even know their names, let alone where they might be found. Frightened and bewildered, he went on with his work as a naval draftsman, watched by those he never saw. His disloyalty in peacetime would lie within reach of the gallows if he continued it in wartime. The temptation to be a spy had gone forever. Once again, Holmes insisted there must be no arrests, no headlines to tell our enemies that their agents had been unmasked. Only by this means could Karl Henschel be used as the means of undermining German intelligence with his false reports.
What the full consequences were, who can say? It is certain that the diversion of 20,000 troops from the Battle of the Marne saved Paris and France, if not England. The battle cruisers of the Royal Navy suffered considerably at the Battle of Jutland in 1916. How much greater their losses would have been had the secret documents concocted by Sherlock Holmes and Jackie Fisher not found their way into the hands of Tirpitz and his staff is a matter of conjecture. Certain it is that my friend was absent for an entire afternoon at Windsor soon after the outbreak of war. He returned and would say little. After a little while he took from his pocket a fine silver cigarette case. Presently he handed it to me.