After several changes of mind, the skipper decided to engage a lascar company that was led by one Serang Ali. This was a personage of formidable appearance, with a face that would have earned the envy of Genghis Khan, being thin, long and narrow, with darting black eyes that sat restlessly upon rakishly angled cheekbones. Two feathery strands of moustache drooped down to his chin, framing a mouth that was constantly in motion, its edges stained a bright, livid red: it was as if he were forever smacking his lips after drinking from the opened veins of a mare, like some bloodthirsty Tartar of the steppes. The discovery that the substance in his mouth was of vegetable origin came as no great reassurance to Zachary: once, when the serang spat a stream of blood-red juice over the rail, he noticed the water below coming alive with the thrashing of shark's fins. How harmless could this betel-stuff be if it could be mistaken for blood by a shark?

The prospect of journeying to India with this crew was so unappealing that the first mate disappeared too, taking himself off the ship in such a hurry that he left behind a bagful of clothes. When told that the mate was a gone-goose, the skipper growled: 'Cut his painter, has he? Don't blame him neither. I'd of walked my chalks too, if I'd'a been paid.'

The Ibis's next port of call was to be the island of Mauritius, where they were to exchange a cargo of grain for a load of ebony and hardwood. Since no other sea-officer could be found before their departure, the schooner sailed with Zachary standing in for the first mate: thus it happened that in the course of a single voyage, by virtue of desertions and dead-tickets, he vaulted from the merest novice sailor to senior seaman, from carpenter to second-in-command, with a cabin of his own. His one regret about the move from fo'c'sle to cabin was that his beloved penny-whistle disappeared somewhere on the way and had to be given up for lost.

Before this, the skipper had instructed Zachary to eat his meals below – 'not going to spill no colour on my table, even if it's just a pale shade of yaller.' But now, rather than dine alone, he insisted on having Zachary share the table in the cuddy, where they were waited on by a sizeable contingent of lascar ship's-boys – a scuttling company of launders and chuckeroos.

Once under sail, Zachary was forced to undergo yet another education, not so much in seamanship this time, as in the ways of the new crew. Instead of the usual sailors' games of cards and able-whackets, there was the clicking of dice, with games of parcheesi unfolding on chequerboards of rope; the cheerful sound of sea-shanties yielded to tunes of a new kind, wild and discordant, and the very smell of the ship began to change, with the odour of spices creeping through the timbers. Having been put in charge of the ship's stores Zachary had to familiarize himself with a new set of provisions, bearing no resemblance to the accustomed hardtack and brined beef; he had to learn to say 'resum' instead of 'rations', and he had to wrap his tongue around words like 'dal', 'masala' and 'achar'. He had to get used to 'malum' instead of mate, 'serang' for bosun, 'tindal' for bosun's mate, and 'seacunny' for helmsman; he had to memorize a new shipboard vocabulary, which sounded a bit like English and yet not: the rigging became the 'ringeen', 'avast!' was 'bas!', and the cry of the middle-morning watch went from 'all's well' to 'alzbel'. The deck now became the 'tootuk' while the masts were 'dols'; a command became a 'hookum' and instead of starboard and larboard, fore and aft, he had to say 'jamna' and 'dawa', 'agil' and 'peechil'.

One thing that continued unchanged was the division of the crew into two watches, each led by a tindal. Most of the business of the ship fell to the two tindals, and little was seen of Serang Ali for the first two days. But on the third, Zachary came on deck at dawn to be greeted with a cheerful: 'Chin-chin Malum Zikri! You catchi chow-chow? Wat dam t'ing hab got inside?'

Although startled at first, Zachary soon found himself speaking to the serang with an unaccustomed ease: it was as if his oddly patterned speech had unloosed his own tongue. 'Serang Ali, where you from?' he asked.

'Serang Ali blongi Rohingya – from Arakan-side.'

'And where'd you learn that kinda talk?'

'Afeem ship,' came the answer. 'China-side, Yankee gen'l'um allo tim tok so-fashion. Also Mich'man like Malum Zikri.'

'I ain no midshipman,' Zachary corrected him. 'Signed on as the ship's carpenter.'

'Nevva mind,' said the serang, in an indulgent, paternal way. 'Nevva mind: allo same-sem. Malum Zikri sun-sun become pukka gen'l'um. So tell no: catchi wife-o yet?'

'No.' Zachary laughed. ''N'how bout you? Serang Ali catchi wife?'

'Serang Ali wife-o hab makee die,' came the answer. 'Go topside, to hebbin. By'mby, Serang Ali catchi nother piece wife…'

A week later, Serang Ali accosted Zachary again: 'Malum Zikri! Captin-bugger blongi poo-shoo-foo. He hab got plenty sick! Need one piece dokto. No can chow-chow tiffin. Allo tim do chhee-chhee, pee-pee. Plenty smelly in Captin cabin.'

Zachary took himself off to the Captain's stateroom and was told that there was nothing wrong: just a touch of the back-door trots – not the flux, for there was no sign of blood, no spotting in the mustard. 'I know how to take care o' meself: not the first time I've had a run of the squitters and collywobbles.'

But soon the skipper was too weak to leave his cabin and Zachary was handed charge of the ship's log and the navigation charts. Having been schooled until the age of twelve, Zachary was able to write a slow but well-formed copperplate hand: the filling of the log-book posed no problem. Navigation was another matter: although he had learnt some arithmetic at the shipyard, he was not at ease with numbers. But over the course of the voyage, he had been at pains to watch the Captain and the first mate as they took their midday readings; at times he had even asked questions, which were answered, depending on the officers' moods, either with laconic explanations or with fists to his ear. Now using the Captain's watch, and a sextant inherited from the dead mate, he spent a good deal of time trying to calculate the ship's position. His first few attempts ended in panic, with his calculations placing the ship hundreds of miles off course. But on issuing a hookum for a change of course, he discovered that the actual steering of the ship had never been in his hands anyway.

'Malum Zikri think lascar-bugger no can do sail ship?' said Serang Ali indignantly. 'Lascar-bugger savvi too muchi sail ship, you look-see.'

Zachary protested that they were three hundred miles off course for Port Louis and was answered with an impatient retort: 'What for Malum Zikri make big dam bobbery'n so muchee buk-buk and big-big hookuming? Malum Zikri still learn-pijjin. No sabbi ship-pijjin. No can see Serang Ali too muchi smart-bugger inside? Takee ship Por'Lwee-side three days, look-see.'

Three days later, exactly as promised, the twisted hills of Mauritius appeared on the jamna bow, with Port Louis nestled in the bay below.

'I'll be dickswiggered!' said Zachary, in grudging admiration. 'Don't that just beat the Dutch? You sure that the right place?'

'What I tell you no? Serang Ali Number One sabbi ship-pijjin.'

Zachary was to learn later that Serang Ali had been steering his own course all along, using a method of navigation that combined dead reckoning – or 'tup ka shoomar' as he called it – with frequent readings of the stars.

The Captain was now too ill to leave the Ibis, so it fell to Zachary to conduct the shipowners' business on the island, which included the delivery of a letter to the owner of a plantation, some six miles from Port Louis. Zachary was making ready to go ashore with the letter when he was intercepted by Serang Ali, who looked him up and down in concern.