Part 17

"What is this germ?" asked a hollow voice from the doorway.

We looked, startled. There stood Saratovsky, more like a ghost than a living being. Kennedy sprang forward and caught him as he swayed, and I moved up an armchair for him.

It is the spirillum Obermeieri," said Kennedy, "the germ of the relapsing fever, but of the most virulent Asiatic strain. Obermeyer, who discovered it, caught the disease and died of it, a martyr to science."

A shriek of consternation rang forth from Samarova. The rest of us paled, but repressed our feelings.

One moment," added Kennedy hastily. "Don't be unnecessarily alarmed. I have something more to say. Be calm for a moment longer."

He unrolled a blue-print and placed it on the table.

"This," he continued, "is the photographic copy of a message which, I suppose, is now on its way to the Russian minister to France in Paris. Some one in this room besides Mr. Jameson and myself has seen this letter before. I will hold it up as I pass around and let each one see it.

In intense silence Kennedy passed before each of us, holding up the blue-print and searchingly scanning the faces. No one betrayed by any sign that he recognised it. At last it came to Revalenko himself.

"The checkerboard, the checkerboard!" he cried, his eyes half starting from their sockets as he gazed at it.

"Yes," said Kennedy in a low tone, "the checkerboard. It took me some time to figure it out. It is a cipher that would have baffled Poe. In fact, there is no means of deciphering it unless you chance to know its secret. I happened to have heard of it a long time ago abroad, yet my recollection was vague, and I had to reconstruct it with much difficulty. It took me all night to do it. It is a cipher, however, that is well known among the official classes of Russia.

"Fortunately I remember the crucial point, without which I should still be puzzling over it. It is that a perfectly innocent message, on its face, may be used to carry a secret, hidden message. The letters which compose the words, instead of being written continuously along, as we ordinarily write, have, as you will observe if you look twice, breaks, here and there. These breaks in the letters stand for numbers.

"Thus the first words are 'Many thanks.' The first break is at the end of the letter 'n,' between it and the 'y.' There are three letters before this break. That stands for the number 3.

"When you come to the end of a word, if the stroke is down at the end of the last letter, that means no break; if it is up, it means a break. The stroke at the end of the 'y' is plainly down. Therefore there is no break until after the 't.' That gives us the number 2. So we get 1 next, and again 1, and still again 1; then 5; then 5; then 1; and so on.

"Now, take these numbers in pairs, thus 3 - 2; 1 - 1; 1 - 5; 5 - 1. By consulting this table you can arrive at the hidden message.

He held up a cardboard bearing the following arrangement of the letters of the alphabet: ____________________________________ |_______1___2___3___4___5_| |_1___A___B___C___D___E_| |_2___F___G___H___IJ__K_| |_3___L___M___N___O___P_| |_4___Q___R___S___T___U_| |_5___V___W___X___Y___Z__|

"Thus," he continued, "3 - 2 means the third column and second line. That is 'H.' Then 1 - 1 is 'A'; 1 - 5 is 'V'; 5 - 1 is 'E' - and we get the word 'Have.'"

Not a soul stirred as Kennedy unfolded the cipher. What was the terrible secret in that scientific essay I had puzzled so unsuccessfully over, the night before?

"Even this can be complicated by choosing a series of fixed numbers to be added to the real numbers over and over again, Or the order of the alphabet can be changed. However, we have the straight cipher only to deal with here."

"And what for Heaven's sake does it reveal?" asked Saratovsky, leaning forward, forgetful of the fever that was consuming him.

Kennedy pulled out a piece of paper on which he had written the hidden message and read:

"Have successfully inoculated S. with fever. Public opinion America would condemn violence. Think best death should appear natural. Samarova infected also. Cook unfortunately took dose in food intended Kharkoff. Now have three cases. Shall stop there at present. Dangerous excite further suspicion health authorities."

Rapidly I eliminated in my mind the persons mentioned, as Craig read. Saratovsky of course was not guilty, for the plot had centred about him. Nor was little Samarova, nor Dr. Kharkoff. I noted Revalenko and Kazanovitch glaring at each other and hastily tried to decide which I more strongly suspected.

"Will get K.," continued Kennedy. "Think bomb perhaps all right. K. case different from S. No public sentiment."

"So Kharkoff had been marked for slaughter," I thought. Or was "K." Kazanovitch? I regarded Revalenko more closely. He was suspiciously sullen.

"Must have more money. Cable ten thousand rubles at once Russian consul-general. Will advise you plot against Czar as details perfected here. Expect break up New York band with death of S."

If Kennedy himself had thrown a bomb or scattered broadcast the contents of the test-tubes, the effect could not have been more startling than his last quiet sentence - and sentence it was in two senses.

"Signed," he said, folding the paper up deliberately, "Ekaterina Nevsky."

It was as if a cable had snapped and a weight had fallen. Revalenko sprang up and grasped Kazanovitch by the hand. "Forgive me, comrade, for ever suspecting you," he cried.