It was in the autumn of 1918, when my medical practice was burgeoning on account of casualties from the recent war, when my friend Sherlock Holmes called upon me in the most unexpected circumstances. Loyal readers of the Strand magazine will, no doubt already be indoctrinated in such exploits of Holmes as the intrigue surrounding the Ruritanian Abdication Crisis. However, at that time Holmes had failed to uncover anything incomprehensible to the human mind for several weeks, and I was beginning to fear for his health.

I was conducting surgery on an elderly Major of Rifles who had lost a leg in the Egyptian campaign, and whom I was treating for scrofula of the stump, when I all of a sudden heard the ghostly, unexpected voice of my friend Holmes.

"I apologize for this peculiar method of gaining entry to your consulting rooms, Watson, but I must beg your company right away."

I looked up, behind me, and all about the room, but could see nowhere my one-time room-mate and companion. I stared at the laudanum bottle I had been about to hand over to my patient.

"The Major was otherwise disposed today, Watson", said the Major. "I have taken the liberty of taking his place. The streets are not safe for me to walk in my customary attire at present."

"But the leg, Holmes", I stammered. "How did you do the leg?"

"Ah, Watson", said Holmes in a voice of immensely pleased conceit, "you have been making the assumption all the time that I had two legs to begin with."

"But Holmes", I protested. "I have seen you run, and jump!"

"Have you, Watson? Have you really?"

"Are you, at present, engaged upon an investigation?"

"An investigation more brutal and savage, perhaps, than any other I have previously been involved in. I consider it normal to see a man's life taken from him by another for the pursuit of criminal gain, Watson; but it is rare indeed for him to be eaten afterwards."

Even I, who have been in Afghanistan, was appalled. "Surely not."

"Just so, Watson. In the past seven days, on Hampstead Heath, there have been seven attacks upon street musicians, each the player of a trombone of some description, and each attacked, if those who heard the attacks are to be believed, whilst executing the closing bars of Gustav Holst's Thaxted. In each case, the victim appears to have been attacked from above, the flesh crushed and cut, the bones splintered, the capital extremity entirely missing in many cases. Each victim's body was also notable for the stench of corruption which hung about it, like gas gangrene."

"Accidental death has been ruled out, then? A recurrent trombone malfunction of some order-"

"- has already been checked for. The instruments were produced by different manufacturers, all of the very highest reputation and with large portfolios of quite living, healthy customers. However, I do not trust the unmedical minds of London's Metropolitan Police, Watson. I require your keen anatomical brain. A fresh body has been discovered on the Heath this very hour. I enjoin you to take the new-fangled subterranean railway to Hampstead. I will be waiting outside the station, though of course you will not know me."