Our cab driver, who smelled of spirits and would surely be on report to his employer, had taken us down Northumberland Avenue but I’d instructed him not to turn down Great Scotland Yard and instead to go on to Whitehall Place, as I detested using the Metropolitan Police Station’s public entrance and preferred instead to go around to the back. There I would no doubt find some constable whom I could have summon Mr. Lestrade. If the matter that he wished to discuss was indeed so urgent it was probably also quite secretive, and would be better spoken of after he’d joined Watson and I in the cab, instead of in his office where the possibility of eavesdropping was more likely.

“I should like to draw some of your blood.” Watson blurted out, having spent the last few minutes in silence staring out of the window. He looked at me, raised his eyebrows questioningly. “Only if you are open to the notion of course. It would be for science.”

“Certainly. I can find no logical reason to refuse.” I would, however, demand that he wait until later in the day and then only after I’d had time for a proper meal. I’d taken a small amount of morphine the night before to ease me into sleep, and some cocaine earlier in the evening to sharpen my wits before confronting Mr. Cokes. I had no wish for him to uncover my habits any time soon.

“I would have thought you to be more excited about the possibility of discovering whether or not there are any abnormalities in your physiology, ones that account for what you now know yourself to be.”

“You expected me to quickly volunteer, not simply acquiesce.” I grumbled, is that correct?”

The doctor fidgeted in his seat, moved slightly so as to better face me. “Granted I’ve known you only a remarkably short time but you seem to be a man who is unrelentingly inquisitive. Surely you wish to know what separates you from ordinary men.”

“Save for my superior intellect?” I smirked, “I should think it to be the fact that my eyes have a peculiar habit of luminescing under the light of the moon.”

“Oh stop being facetious Holmes. I have...” he ceased in mid-sentence then leaned in so as to speak more surreptitiously; as if the half-drunken driver could have heard anything we spoke of over the clatter of the horses’ hooves against the pavement. “I have been conducting laboratory research into the matter of what makes were-beasts and other homo monstrum who and what they are.”

“And?” my curiosity was roused.

“Well further tests are in order, hence my request, but I believe there just might be a chemical signature present in the blood of individuals such as myself...or ourselves, depending upon what the results of the test are. Until now I’ve only had chance to take a couple of blood samples save for my own.”

“And if your findings indicate that I am in essence only a variation of what you are?”

“I should think that would be up to you Holmes. If your reputation is to be believed you had little compunction about catching ordinary human criminals when that was what you believed yourself to be.”

“Catch, Watson, that is the key word.” I remarked, “I did not take it upon myself to behead them or shoot them with poison darts and dispose of their bodies via submersion in vats of industrial chemicals.”

“Yes...but you know as well as I do that you can’t simply turn these types of matters over to the police.”

“Indeed.” I muttered, staring out of the window blankly.

“Which is why I felt my only option in dealing with Mr. Cokes was to eliminate him myself. It was not something that I desired, but I could not know what I knew about him and simply let his crimes go unchecked. Besides, you said yourself that you haven’t had to kill every monster that you’ve come across. There was the Korrigan, remember?”

I said nothing, which to my clever new companion was every bit as good as an admission of guilt.

“Holmes you didn’t? You said that you’d let him be with only a warning.”

“At first Watson, at first. Some months later I caught him using his abilities to foretell the deaths of wealthy widow women; comforting them into their graves and then leaving their families with nothing.”

“So you killed him?” Watson seemed shocked.

“It is what I do, remember?” I snapped, “I slit his throat using a blade laced with hemlock, the only way to guarantee a Korrigan’s death, then burned his remains in the forest.”

“His behavior was quite despicable, but do you truly think him to have been worthy of death?”

“In his belongings I found a diary that contained the descriptions and addresses of nearly a dozen children. Do you know what Korrigans do with children Watson? They replace them with changelings, the original child taken away for some nefarious purpose that one can only postulate about.”

He thought for a moment. “That is awful, I will grant you that. But you did not know of the diary at the time you ended his life.”

“Are we really to have this conversation? I hunt and kill things, things very similar to you I might add. If you are uncomfortable with that fact then I suggest we end this partnership as it is unlikely to be a very fruitful one.”

“As much as I find your blatant lack of tact distasteful I do believe your actions to be mostly well intentioned. That coupled with the fact that I, a man who has pledged to do no harm, took it upon himself to murder a criminal, means that I do not find myself in a position to judge you Holmes.” his words had been harsh, and we sat quietly for a moment before he spoke again. “Besides, perhaps some of my more well developed manners will rub off on you.”

At that I fought back a smile and let out a single laugh.

“I must ask.” the doctor began, “Have you ever taken the time to thoroughly examine one of the corpses?”

“Yes, yes Doctor. You’ll find the results in my library in a volume entitled ‘Post-Mortem Analysis of Lusus Naturae’. Regardless, this conversation is at an end.” I pointed out of the window. “The Yard is just ahead.”