'Wise man,' Holmes murmured, 'wise man.' He was silent for a while. His eyes gazed into space with a strange burning vacancy. For just a moment it seemed to me that beneath his calm, rational, superior self there struggled another more intense and restless soul – not at all European – but what would be recognised in the East as a 'Seeker'. Then with a conscious effort he broke off his singular reverie.

'Have you breakfasted?' he asked. I noticed an empty breakfast tray pushed away to the side.

'A cup of coffee? No? Well then, if it is not too early, could I trouble you to accompany me to the Bombay Natural History Society that you mentioned last night.'

'Mr Symington, the secretary is at the premises quite early, Sir. He works on his own researches there as it is much cooler in the mornings.'

'Excellent. Then let us not waste any time.'

He carefully coiled up the tube of his hookah, and taking off his dressing gown, put on the grey linen jacket he had worn the day before. Unlike most Europeans in India he did not wear a pith helmet or a topee, but made do with a light cap, of the kind which I think is called a deerstalker.

We quickly made our way downstairs. Before leaving the hotel Mr Holmes went over to the reception desk where he scribbled a chit and sealing it in an envelope handed it to one of the hotel clerks there. I suspected that the note was for Strickland. Then Mr Holmes and I left the hotel in a ghari.

There was the tang of saltwater in the air as we rattled down the beach road, where near-naked boys were selling coconut water, fresh in its own shell, and two ash-covered sadhus were performing their sun worship in the sea. Things were less peaceful at the Borah Bazaar where shopkeepers, vendors, tongawallahs, coolies, and pedestrians of all kinds were noisily beginning their day. Finally we arrived at the brick bungalow of the Bombay Natural History Society.

We waited in a large hall while the chaprasi went to find Mr Symington. The whole place was filled with an extraordinary variety of rather moth-eaten exhibits of stuffed birds and animals behind labelled glass cases. After a few minutes the chaprasi returned.

'The sahib awaits you. Please come this way.'

Stumbling over stuffed crocodiles and the hoofs of sambhar floor rugs, we followed him through a corridor and into a long chamber lined and littered with botdes of various chemicals. Broad, low tables bristled with retorts, test-tubes, and littie Bunsen lamps, with their blue flickeringx flames. An overpowering smell of formaldehyde permeated the air. It did not seem to bother Symington, who sat behind a long marble-topped table sorting out what looked to me like dirty duckweed with the aid of a pair of tweezers. He was a small, untidy man with a bald shining head that was covered scantily on the sides and back with tufts of grey hair. Raising his head slightly he peered through his thick spectacles with weak watery eyes.

'Hello, is that you Mookerjee?'

'Yes, Mr Symington. How are you?'

'As well as can be expected. By the way, I never got the chance to thank you for that specimen of Primula glacialis. [13] It's a real feather in my cap, you know. Even Hooker [14] never got one.'

'Well, Sir, the true specimens only grow around twenty thousand feet. It is difficult for human life to manage at those heights.'

'But somehow you did, didn't you, you old devil,' he chuckled, pushing up a pair of spectacles that always had a tendency to slip down his nose. 'Now, who is your friend here?'

'Mr Sigerson is from Norway, Sir. He is a… an… ah… explorer.'

'An explorer? How interesting. Very glad to meet you, Sir. How can I be of service to you?'

'If it is not too much trouble,' said Sherlock Holmes, 'I would like to consult whatever literature you may have on Hirudenia!

'Hirudenia? Ah. You have come to the right place. We have every standard work on the subject, including a few very special and important reports that I may presume to say are not to be found anywhere in Europe at present. Please follow me.'

He led us into a long narrow chamber lined on either side with tall mahogany bookcases. He opened the glass-framed doors of one and peered short-sightedly at the collection of books inside.

'Could I trouble you for that?' He turned around, pointing at a low step-ladder nearby. I carried it over to him.

'Thank you.' He climbed up the first three steps and, peering closely at the spines of the books on the top shelf, commenced a litany of the names of the authors, who were, I suppose, all experts on 'Hirudenia] whatever that was.

'Fowler.,. Merridew… Konrad… Hackett, humm… Hackett. Don't think he'd be any good to you; fellow deals with invertebrate phyla in general. Konrad and Merridew are best especially on the hirudenia of this country.' He pulled out two slim volumes and, blowing the dust off the top, handed them to Holmes. 'Hope you find what you need in here. Not too fond of them myself. Strictiy a flora man. Blood thirsty brutes killed half my pack animals on an expedition once. Well, I will leave you to your research.'

Holmes sat on the step-ladder and began reading. He flipped over the pages of the first book impatiently, and when he got to the end put it aside with a snort of disgust. He must have found what he was after in the second book for he suddenly stopped flipping the pages and gave a little cry of triumph.

'Ha! Ha! Capital!' he chuckled, twitching with excitement, poring carefully over the page, underlining each sentence with a nervous finger. He occasionally paused to scribble brief notes on his cuff. After a long time he turned to me, shaking his head with feigned sorrow. 'Ah, me! It's a wicked world; and when a clever man turns his brain to revenge, it is the worst of all. I think I have enough information now…'

'Mr Holmes! You have solved…'

'Exactly, Mr Mookerjee. Only that I arrived at my conclusions last night, aided in part by the invigorating fumes of a few ounces of native tobacco. This…' he said, closing the book with a thump, '… is merely confirmation.'

'But I don't understand how…'

'Patience,' he replied. 'All will be revealed in good time, I assure you. I have my own peculiar way of working, which you must forgive me. And now for a little recreation. I would like to avail myself of the services you offered to me on our first meeting aboard the ship, and be introduced to the sights of this city'

We left the library and, going down to the laboratory, said goodbye to Symington. The old botanist shook Holmes by the hand and made a not very subtle bid to elicit information about Holmes's purported explorations.

'Well, Mr Sigerson, I wish you the best of luck in your venture. Mookerjee here knows the ropes and ought to be able to safely guide you to… ahh… where did you say you were going to pursue your explorations?'

'I did not,' said Mr Holmes, the merest hint of amusement colouring his voice. 'But your cooperation has been invaluable, and it would be ungrateful of me to be reticent. In all confidence, I am telling you that it is my intention to enter Thibet and visit the fabled city of Lhassa.'

As I had feared, Symington at once began to greedily enumerate a long list of plant specimens we were to obtain for him in the highlands of Thibet.

'… remember, I want the Blue Poppy and the Stelleria decumbens, root and all… and don't get discouraged by the spines… the Gentiana depressa must be of the dwarf variety otherwise…'

Offering tactful but non-committal replies, I managed to finally extricate Mr Holmes and myself from the company of Symington, who would have even walked with us down the street with his endless catalogue of botanical needs, if we hadn't luckily chanced upon a ticca-ghari at the gate of the bungalow. We hurriedly boarded the carriage and fled.

Sherlock Holmes leaned back on the cracked leather seat of the ghari and chuckled. 'The etymology of the word "enthusiasm" can be traced back to the Greek enthousia, meaning to be possessed by a god or demon. But it never occurred to me till today how true the word has remained to its origin.'