At this precise moment, the silence was shattered once more, but not by a pistol shot, or a chunk of ice, or the sound of wheels turning in the slippery snow. This time, we heard the voice of a man.

‘Mr Mitter!’

Who was this? Why did the voice sound vaguely familiar?

‘Listen carefully, Mr Mitter,’ it went on. ‘You must have realized by now that I have got you where I want you. So don’t try any clever tricks. It’s not going to work and, in fact, your lives may be in danger.’

It was some time before the final echo of the words died down. Then the man spoke again.

‘I want only one thing from you, Mr Mitter.’

‘What is it?’ Feluda shouted back.

‘Come out from where you’re hiding. I would like to see you, although you couldn’t see me even if you tried. I will answer your question when you come out.’

For a few minutes, I had been aware of a strange noise in my immediate vicinity. At first I thought it was coming from inside the car. Now I turned my head and realized it was simply the sound of Lalmohan Babu’s chattering teeth.

Feluda rose to his feet and slowly walked over to the other side of the car, without uttering a word. Perhaps he knew under the circumstances, it was best to do as he was told. Never before had I seen him grapple with such a difficult situation.

‘I hope,’ said the voice, ‘that your three companions realize that a single move from them would simply spell disaster.’

‘Kindly tell me what you want,’ said Feluda.

I could see him standing from behind one of the wheels. He was looking up at the mountain. In front of him lay a wide expanse of snow. The pine forest started at some distance.

‘Take out your revolver,’ commanded the voice. Feluda obeyed.

‘Throw it across on the slope.’ Feluda did.

‘Do you have the Kodak container?’

‘Yes.’

‘Show it to me.’

Feluda took out the yellow container from his pocket and raised it.

‘Now show me the stone you found in it.’

Feluda slipped his hand into the pocket of his jacket. Then he brought it out and held it high once more, holding a small object between his thumb and forefinger.

No one spoke for a few seconds. No doubt the man was trying to take a good look at the diamond. Did he have binoculars, I wondered.

‘All right,’ the voice came back. ‘Now put that stone back into its container and place it on that large grey boulder by the side of the road. Then you must return straight to Simla. If you think …’

Feluda cut him short.

‘You really want this stone, don’t you?’ he asked.

‘For God’s sake, do I have to spell it out?’ the voice retorted sharply.

‘Well then, here it is!’