He paused to see the effect of his speech on Sherlock Holmes, who, unperturbed as ever, looked straight back at him with calm dignity.

'You do not believe me? Maybe a demonstration would be in order. I owe you that, at least. You threw me into that chasm… and, well, I am a man who believes in returning favours.'

He raised his hands, his fingers forming strange mudras or occult gestures. It may have been my overwrought imagination but I distinctively felt some energy move across the room. The lamps flickered, and I felt a strange sensation in the pit of my belly, as if a hand had grabbed me there. The two soldiers may have felt something too, for I clearly heard both of them suck in their breath in audible gasps.

The effect on Mr Holmes was alarming. His eyes grew wide with terror. His mouth opened to emit a sharp scream, which ended in a low, frantic gurgle. His body swayed forward, his hands stretched out, flailing wildly, as if he was balancing for dear life on the edge of something terrifying. I was certain that he was being subjected to some kind of powerful mesmeric force that actually made him see and experience falling over a precipice. I am not inexperienced with this strange force, having once been unhappily subjected to a seance by Lurgan [36] , back in Simla – but I need not go into that now. But the suddenness and overwhelming force of this present phenomenon was beyond the bounds of anything imaginable. Slowly Mr Holmes seemed to lose his balance, and with a great cry fell forward onto the floor. In spite of the armed guards, who had their weapons trained on me, I rushed forward to assist my stricken friend.

Just at that moment the sharp report of rifle-fire broke into the room. What in heaven's name was going on out there? Had the Chinese soldiers commenced firing on the mob? Professor Moriarty dropped his hands and turned his head in the direction of the fusillade. He barked an order to a guard. 'You! Go to the front quickly and ask His Excellency the Amban what is going on. Report back immediately'

I was tending to Mr Holmes and trying desperately to resuscitate him. I was very gratified to note that he was not deceased or even critically incapacitated. He was breathing heavily, gasping sometimes, but, feeling my hands on his shoulder, he opened his eyes. For just a brief moment he appeared somewhat bewildered – a state I had never seen him in before – but his indomitable strength of character quickly reasserted itself and his eyes resumed their normal alert and intelligent quality. I helped him to a chair.

'You have recovered, Holmes?' gloated Moriarty. 'Good. Very good. Pathetic as your mental powers are when compared to mine, they never fail to astonish me. Any other man would be a gibbering wreck by now. But I should not have expected anything less from the great Sherlock Holmes.'

A few more bursts of gunfire echoed outside. Moriarty drew aside the curtain from the window beside him and peered out.

'Don't expect your dirty Thibetan friends to save you,' he said, turning around and facing us again. 'A few more volleys from the guard's rifles and they will all take to their heels. "A whiff of grapeshot" Eh!… "A whiff of grapeshot". Bonaparte knew how to deal with rabble.' The Professor bent forward over the desk and glared at Holmes with manic eyes.'… and he knew power; crude as his notions of it may have been, he knew how it had to be wielded – with force and ruthlessness!'

'Brag and Bounce,' I thought to myself. The blighter's conceit was really insufferable. I could not help but offer a refutation, though I regretted it the moment I did.

'Yet, if I may be permitted a historical retrospective,' said I, delicately,'the Corsican brute ended his life as a wretched prisoner of His Sovereign Majesty, King George the Third.'

'Yes, fool,' he turned to me with a snarl. 'He failed because his powers were only those of the intellect, of military stratagems and political plots. Great as such an intelligence may seem to a dolt like you, they are as nought against the power of the primordial mind. But perhaps my demonstration on Holmes did not convince you. Perhaps you would like one yourself?'

Before I could offer a polite refusal he held up his right hand and pinched his index finger and thumb together. Although I was about ten feet away from that dreadful man, I distinctly felt something tweaking my nose – and hard! I nearly jumped out of my bally skin.

'Does this quite convince you now, my fat Hindu friend? Or perhaps a little more pressure would reinforce the salutary effect of this lesson.'

'Yeow! Ow! Ow!' I could not but help yell out. 'Eduff! I dink I am abdolutely codvinced. Yeow!'

He did not release my nose immediately, dam' his eyes, but held on even more firmly for a few moments more, before finally letting go after a last savage tweak.

'Yeow!'

While I rubbed my poor nose, Moriarty leaned back on his chair and resumed his boasting speech.

'Awesome as the force I have just demonstrated may seem to you, it is nevertheless subject to the laws of nature and the cosmos, and thus inherently limited. Others, though only a few, possess such powers as mine. But there is a way to increase its strength – a hundred fold, a thousand fold – and I have, at long last, found the way.'

He raised a finger. As if at a command the scroll on the desk unrolled itself and lay flat on the surface.

'And this will lead me to it.' He pointed to the circular geometrical painting, its colours gleaming like living rainbows under his deathly white finger. 'And only I will be the master of it. This time none of those weak-minded lamas with their tiresome pieties will be permitted to come between me and my destiny.'

As Moriarty ended his mad diatribe, the yelling of the mob outside became distinctively louder; suddenly the window on his side, behind the guard, exploded, as a rock smashed through it and flew into the room. By Jove! The demonstrators were shying missiles in retaliation to the shooting. The guard turned around in surprise.

Mr Holmes did not hesitate to seize this opportune moment. He leaped forward and fisted the cad soundly on the side of his head. It was a well-executed and powerful blow – obviously Sherlock Holmes was fully versed in the manly art of pugilism -for the guard was effectively incapacitated by that single cuff.

The speed of my own reflexes were not very much behind those of Mr Holmes. My many experiences in various ticklish situations had honed my reactions to a fine edge; and anyhow, fear is always a powerful goad to speedy action. Such is the tremendous galvanic force of the trained human reflex, that before I had even conceived a thought of assailing my foes, my fingers were already curling around the base of the shining lampion on the small table by my side. And before Moriarty could have any idea of what I was up to, I had picked it up and hurled it straight at him.

Unfortunately, I missed. I was a good three feet off the mark. The lamp flewpast the villain and struck the wall behind, and fell broken on the floor. He didn't even flinch, just looked directiy at me with those terrifying eyes. I was, I will admit, a trifle abashed by this turn of events.

'I should opine that the damaged article was not particularly valuable… ' I said, rather sheepishly.

'Silence, fool!' he snarled, the veins on his bulging forehead twisting and jerking in an appalling fashion.'Did you think to save your miserable skin by such a pitiful trick?'

He raised his hands as if to deliver another one of his horrible spells, while I stood there helpless as a frog before a cobra. But then I noticed a flickering glow behind him, and suddenly the Professor was jumping about, screaming like a lunatic. The glow became brighter to reveal the flames devouring the edge of his robe and the carpeted floor, where the oil from the broken lamp had spilled and ignited.