Holmes mused for a moment. “I believe Your Grace may be mistaken in your interpretation of what took place that evening.”
“How so, Mr. Holmes?”
“It may be true that your late husband’s spirit abstracted the stones, and that they will never again be seen by mortal eyes. But I ask you to reconsider your belief that their removal was a punishment or revenge upon you. True, your husband took back the jewels he had once given you. But were they not insured?”
The duchess nodded. I confess I was taken aback by my friend’s words, as I knew what little respect he had for the deceit of mediums and the popular belief in spiritualism. But I knew Holmes well enough to hold my tongue, and smiled indulgently at the duchess.
“Perhaps,” said my friend, “the late duke took the diamonds as a kindness to you, rather than a punishment.”
She flushed and raised a gloved hand to her mouth. Holmes nodded kindly. They understood one another, although I confess I was baffled.
Holmes bade the duchess farewell and we left the hotel, catching a hansom in Dover Street. When we were on our way I asked Holmes what he meant by encouraging the foolishness of an old lady.
“Sometimes,” he replied, “it is kinder to compound a deception, and Her Grace is right on one point, I am sure. She will never see her diamonds again. We, on the other hand, may be more fortunate. Now my friend, I must continue alone and ask you to wait for me at Baker Street while I pursue certain theories.”
I felt a little hurt by this suggestion, but knew there was little sense in arguing. I spent the remainder of the day in our rooms trying to write a coherent account of all that had occurred and reviewing the evidence we had so far gathered. I formed for myself a small theory which accounted for some, at least, of the curious features of the case. I reasoned that Madam Spinarossa must have been responsible for the theft of the diamonds, and that she had achieved it by the use of an ingenious device consisting of two false hands, made perhaps of India rubber, separated by a stiff rod, perhaps of telescopic construction. This she had concealed beneath her robes until the lights were doused, when she took out her device and laid it upon the table between the duchess and Matilda Grayson, each of whom took one of the false hands in her own, believing it to be that of the medium. This left Spinarossa’s own hands free to remove the tiara and prise out the diamonds, covering the noise with groans and sighs, while a confederate hidden behind the window curtain spoke with the voice of the duke.
Although I could see some flaws in this theory, and it did not cover all the facts, yet I felt sure Holmes would be impressed by my deductions when he returned. When he finally appeared, at a little after eight, however, my suggestions caused him amusement.
“I congratulate you, Watson. You have hit upon the answer!” said he. “The medium must have owned a set of rubber hands. But wait! What became of those hands? How did she conceal them from a police search? And how did her confederate at the window gain entry and exit without being seen, when the window had clearly not been opened for many years? No, I fear we must seek both a simpler and a more radical explanation for what went on in that small dark room. You are, however, quite right in your basic deduction that the medium took the diamonds. Only the story does not end there and, I fear, we will uncover further crimes committed in pursuit of those stones. Even now, friend Lestrade is waiting for us in Bruton Street to take the matter to its conclusion. I should be most grateful for your help in that conclusion. Will you join me?”
I smiled and nodded, though I felt crushed by Holmes’s summary rejection of my deductions.
“Good man. You have your revolver? Excellent.”
We caught another cab and made the short journey to the end of Bruton Street, where we alighted beside Lestrade and four constables. Holmes had obviously indicated to the inspector that something was afoot, for Lestrade’s face was grimmer than usual as we set off along the pavement.
As we walked I whispered to Holmes, “Is this the solution to the diamond theft, or to the mystery of Hartshorne’s front door?”
“Why, to both, old friend, to both.”
We stopped before a dark house bearing the number 38A. Holmes raised a hand for us to wait, and approached the door. He produced a dark lantern and by the narrowest blade of light examined the entrance. Then he put out a hand and tried the handle. The door opened and I heard his intake of breath. He beckoned us to follow, and we entered a dark hall. There was a slaughterhouse smell in the air, and I prepared myself for the worst. Holmes led the way, cutting through the blackness with a thin beam from his lantern. At the end of the passage were two doors, both standing open. Holmes illuminated the space beyond first one, then the other.
“Lestrade,” he said, “please keep your men back until I have examined this room.” The inspector sighed and accompanied Holmes and myself through one of the doors.
“No need for silence now,” said Holmes, “we are too late to change the course of events.”
He lit the gas, and a ghastly scene met our eyes. The room was unfurnished save for two chairs, a small table, and two makeshift beds upon the floor. Lying beside them, upon the bare boards, were two bodies. They were both young men with dark hair and skin, and both had deep wounds in their throats. A dark brown puddle surrounded the two figures. Their limbs were contorted and their faces racked with exertion and fear. Holmes asked us to remain by the door while he examined the bodies and the contents of the room. Some objects on the table caught his particular interest and he inspected them with his glass for some minutes. Then he gestured for us to join him. I examined the bodies, though there was clearly nothing that could be done for them. Then I joined Holmes at the table. Laid out there was a singular array of objects. There were the separate parts of a large old-fashioned door lock with a brass facade, a pile of brass screws, a leather bag containing tools, a small metal lantern, a pile of grey powder, a revolver, the remains of a simple meal, and an array of human body parts, laid out neatly like specimens in a museum. There were eight fingers, two toes, two ears, a fleshy lump which was probably a nose, and several other pieces which I could not identify. These grim trophies were not bloody, but had evidently been washed and made presentable, which somehow made their appearance still more horrific. I glanced over at the two bodies. Clearly the specimens on the table had not originated there.
“What is all this, Holmes?” I asked.
The great detective said nothing, but pointed to the wall beside the door. Here a large mark or cipher had been drawn in blood upon the bare plaster. At first I thought it was a cross, but the lower tip was pointed and I realised that it represented a sword or dagger.
“What is it?” said Lestrade.
“That,” said Holmes, “is the Scarlet Thorn.”
We were, I think, too affected by the contents of that room to discuss the matter there. Lestrade left his constables to record the details and remove the bodies while he and I returned with Holmes to Baker Street, where a full explanation was promised. Once settled in familiar surroundings our spirits lifted and, having lit my pipe, I pressed Holmes to illuminate the darkness.
“First of all,” he said, “I must tell you that a very great man has died. Indeed, he has been murdered, and in the most unpleasant circumstances. But I am getting ahead of my story. What we have just witnessed was the final scene of what began as a simple drama, planned by a group of ruthless criminals as a means of raising money. I am speaking of a particularly brutal Italian secret society known as the Spina Rossa, or Scarlet Thorn, which hired a clever thief to abstract the diamonds of the duchess of Caradoc. Some of the details of the case remain obscure, but I suspect they anticipated a burglary, or some other simple robbery. However, the man they had hired was none other than Salvatore Barozzi, who had perhaps the third or fourth most subtle criminal mind I have ever encountered. I knew him many years ago when I was myself considering a career on the stage. He was an actor, and an uncommonly good one. But his talents were put to evil ends, and latterly he made his living by assuming some pious, trustworthy, or harmless character and tricking his way into the houses of the rich. He was that most dangerous specimen, the criminal who loves his crime, the impostor who relishes each new imposture. When the Spina Rossa commissioned him to seize the Caradoc diamonds, he began to research the life and mind of the duchess, and conceived a meticulous plan based upon her natural weaknesses. He assumed the character of an elderly medium.”