Outside Bombay the train slowed down and stopped at a small station. Probably the tracks were not clear ahead and the points had to be changed. A harassed looking Eurasian ticket-collector entered our carriage, his sour face, under an uncomfortably large pith helmet, glistening with perspiration. He eyed me in a very unpleasant way. 'Hey you, Babu! What are you doing here? Nikal jao Jaldi!'

'This gentleman is travelling with me,' said Holmes quietly but firmly. 'We have taken the whole coupe. Here are our tickets.'

Wiping his face with a none too clean handkerchief, the ticket-collector pored over the damp sheaves of passenger lists on his clipboard, and at last grudgingly punched our tickets. Just as he was leaving Sherlock Holmes spoke. 'Excuse me, would you by any chance have a piece of chalk with you?'

The ticket-collector seemed rather surprised by Mr Holmes's request, but extracted a small stick of white chalk from the pocket of his faded blue uniform and proffered it to Holmes. Ticket-collectors and guards generally carried pieces of chalk with them to put temporary markings on the side of carriages for the purpose of identification.

'Thank you very much,' said Holmes as the ticket-collector tucked his clip-board under his arm and left. I also got out of the carriage to search for the dining-car. It was, thankfully, not too far away, and I was able to purchase some cold Murree beer for Mr Holmes and tonic water for myself. Clutching these I hurried back and I was just in time, for as soon as I reached our carriage the train started.

Mr Holmes was also outside the train, and he climbed in after me. As he reached for the door I noticed that his hands were covered with chalk dust. He then went into the toilet attached to our carriage. When he came out I noticed that he had washed his hands thoroughly.

As the train picked up speed and roared through the hot Indian night, Mr Holmes and I settled down to pur journey. Drinking the cold beer and tonic water, and eating Cabuli grapes and pistachio nuts I had earlier purchased at the Bhindi Bazaar, we discoursed amicably on matters of life, art and philosophy before finally turning in for the night.

Around three o'clock in the morning I was rudely woken from my slumbers by a tremendous commotion from the neighbouring carriage – even afire-arm being discharged. Probably the tommies had had too much to drink and were, as usual, being obstreperous and a disgrace to their uniforms. Someone also seemed to be yelling something, in Hindustani, but I could not be sure. After a while the uproar subsided and gentle Morpheus once more enfolded me into his embrace. But just before falling asleep I thought I heard Sherlock Holmes chuckling to himself in the darkness of the carriage.

I awoke to find Mr Holmes up in his purple dressing gown, smoking his pipe and reading The Times of India, while a railway bearer in white livery was serving breakfast on the raised drop-leaf table.

'Good morning, Huree,' said Holmes, turning a page of the newspaper. 'I trust you are well rested.'

'Oh yes, Mr Holmes. I slept like a baby. Only the bally hullabaloo in the next carriage disturbed my slumber somewhat. Surely it woke you up too, Sir?'

'Babuji!' said the bearer, who had, rather impertinently, been listening in on our conversation.'Last night two dacoits broke into the next carriage.'

'How did you know that?' I asked in the vernacular.

'Babuji, I entered this rail-ghari with chota-hazris at Jalgaon junction early this morning. There policewallahs took one dacoit from the next carriage. The ticket-babu told me that two dacoits had tried to rob a carriage full of Angrezi soldiers. Hai! Bewakoofi On learning their mistake, one fool jumped out of the window. The other was shot in the leg by a soldier sahib's bundook. I must go now to serve other hazris.'

'It is dashed unusual of dacoits to enter a carriage full of armed soldiers,' I mused, after translating the waiter's story to Mr Holmes. 'Generally, criminals of this sort are more careful and prepared in their enterprises.'

But Mr Holmes did not seem to share my doubts. There was a knowing twinkle in his eyes.

'By Jove, Mr Holmes,' I exclaimed, 'I perceive you have a fair idea about the matter. I beg of you not to perpetuate my ignorance.'

'Well,' said he, putting away his newspaper, 'it all begins with the drawing of an open hand. Remember I asked you last night what it might mean.'

'Yes, Sir. I told you it was the symbol of Kali.'

'I noticed such a sketch done in chalk, on the side of our carriage, just before the train left the station at Bombay.'

'But I saw nothing.'

'You saw, but you did not observe. The distinction is clear. For example, you must have made hundreds of train journeys, and frequently seen the wheels on the carriages.'

'Yes, Sir.'

'Then how many are there on each carriage?'

'How many? Four, I suppose. I cannot be sure.'

'Quite so! You have not observed. Yet you have seen. That is my point. Now I know that there are eight wheels on every carriage because I have both seen and observed. But getting back to the subject at hand: when I first saw the drawing I knew that it could only be either one of two things: a child's innocent scrawl, or a mark left for some definite purpose. When you informed me that the handprint was a symbol of the goddess Kali, and consequently of the Thugee cult, I knew that the game was up and our flight had been discovered.'

'But who could have done it? Mr Strickland only made reservations for our compartment just before the train came into the station, and we have been inside the carriage ever since then.'

'It could have been any one of those beggars clinging to our carriage windows. Probably Moran had taken the precaution of having watchers at the station, just in case I made a bolt for it.'

'Probably Ferret-Face was one of the watchers, Sir.'

'It is more probable that he was the organiser, and had a number of watchers covering various places at the station and reporting back to him when they spotted anything.'

'Yes, of course. I stand corrected, Mr Holmes.'

'Now, I could not call for police assistance merely because of the drawing, even supposing that we could find such help on a moving train. We must bear in mind that the police would have wanted to know my position in the scheme of things, which would have been rather awkward to explain. There was also the possibility that Moran could have disguised some of his men as policemen to take us unawares. So with not many options left, I rubbed out the sketch on the side of our carriage and chalked a similar one on the side of the next carriage, the one full of armed soldiers.'

'Acha! Of course. So they were Thugs who entered the carriage last night, not dacoits. Goodness gracious! If it were not for your vigilance, Mr Holmes, there would have been handkerchiefs twisted around our throats this morning. Baapre-baap!'

'It need not have come to that. There was always my revolver. But that would have been cutting it rather fine. Now what do we have here?' Holmes raised the cover of a dish and sniffed appreciatively. 'Ah, bacon and eggs. Could I serve you some, Hurree. If I am not mistaken, the consumption of a few rashers of bacon does not constitute any fundamental violation of observances in your particular faith.' We arrived at Delhi that night around eleven o'clock. I got up from my berth and peered out of the carriage window at the unlovely, fortress-like station built of dull red sandstone. It was hot, much hotter than Bombay – and very dusty. A lone bhisti spraying the platform from his buffalo-skin mussak, did not help to settle the dust or cool the air. The beggars were noisier here. I purchased a paan from a one-eyed vendor and chewed it till the train thankfully pulled out of the station. A little breeze wafted though the coach and I fell back to sleep.