'So he must, too. Will you look at the oars now, how they beat? They are like the wings of a great low-flying, strong-flying bird, a vast celestial swan.'

Martin laughed with pleasure. 'It is Pindar, I believe, who makes the same comparison,' he said. 'But I see no chains: the men seem free to move about.'

'Hassan tells me that the Mubara galleys have never employed slaves; and that is another parallel with the penteconter.'

'Yes, indeed. Shall we catch her, do you suppose?'

'Why, as to that,' said Stephen, 'my opinion is not worth a straw. I will only observe that your Thucydides speaks of a galley that went from the Piraeus to Lesbos between one noon and the next or rather less, which is some ten miles in every hour, a most terrible pace.'

'But, my dear sir, Thucydides' boat was a trireme, if you recollect, with three banks of oars, which must surely have propelled it three times as fast.'

'Is that right? Perhaps we shall catch her, then. But if we do not, and I must say that little small island seems awkwardly placed for sailing round, then I make no doubt Captain Aubrey will pursue her right into the harbour of Mubara itself. The only trouble is, that if they get there first, having been obviously chased, even attacked, the effect of surprise will be lost entirely, and they may oppose our landing with force, perhaps with extreme violence.'

'Doctor,' called Captain Aubrey, breaking off his calculations, 'pray desire Mr Hassan to keep himself and all the Turks out of sight.'

Two possible solutions: he could make a direct dash, hoping to intercept the galley before Hatiba. The inshore breeze was likely to freshen as the land grew even hotter, and it might well back a point or two; while the turning tide would counteract the eastward-setting current in less than an hour. But would that be soon enough? The galley could probably go faster if she chose. How much faster? He had seen one row at ten knots for a short burst. And if the Niobe, sagging to leeward, failed to weather the tip of the reef, the galley would run clean away from her, rounding the point and then setting those immense lateen sails with the wind right aft to race down the bay and give the alarm in Mubara, perfectly certain that she had been chased. On the other hand he could stand out to sea for a while, calming the galley's present apprehensions and opening the narrow entrance so that later in the day (or even by night) he could sail placidly in under topsails, with a nonchalant air, perhaps with French colours. Yet that meant loss of time, and he had not needed the Admiral to tell him that speed was the essence of attack. He glared at the remote islet with the utmost intensity, measuring the angle, estimating the ship's leeway and adding the thrust of the current and the effect of the coming slack water. Already the heat was making him sweat and the island quiver, and in an exasperated aside he said to himself 'Lord, the comfort of being under orders, the comfort of being told exactly what to do.' Then raising his voice, 'Topgallants. Lay aloft, lay aloft.'

As the upperyardmen raced up the ratlines he watched the galley with the greatest care, and when the sails flashed out aboard the Niobe he saw the man in crimson trousers drop his fan, snatch up a long round-headed pole and start beating time with it, shouting at the rowers as he did so. The oars cut up more white water and the galley's speed increased almost instantly, far sooner than the Niobe's.

'There is no doubt but they are thoroughly frightened of us,' said Jack, and he made up his mind to stake everything on the direct dash: if the galley was already aware of his motions there was no point in standing out to sea.

Having given orders to make all possible sail he said to Stephen 'Perhaps we should let poor Hassan come on deck, now there is no call for any disguise. You may tell him that it will all be decided in thirty minutes or so: and if the Turks were to stand along the weather-rail their weight would make the ship a trifle stiffer.'

Royals and flying kites caused the Niobe to heel another strake, but they did not propel her at much above six knots ;it first. The galley drew away: for a good five minutes she drew away, but then her lead steadied, and so they ran, straining to the utmost, over the mild gently rippling sea, at just the same distance from one another. The half-hour glass turned; the bell was struck. The fierce predatory faces lining the Niobe's rail did not change in all this while, nor did any man say a word; but when she began to gain on the chase all the faces lightened, even at the first few barely perceptible yards, and they uttered a general howl.

'The rowers are beginning to tire,' said Jack, brushing the sweat from his eyes - the sun was full on him as he leant out over the hurrying sea - 'And I don't wonder at it.'

Another cable's length of gain, and now the tide was on the change. The Niobe, right out in the fairway,profited much more than the chase and she began to overhaul her fast. The tension mounted higher still. By now it was almost certain that the ship could not weather the island, could not get round without tacking - a fatal loss of time - yet on the other hand the likelihood of her cutting the galley off before Hatiba was growing every minute..

But now there appeared a danger that Jack had not foreseen: far on the galley's starboard bow there was a gap in the white line of surf, a narrow passage through the reef into the lagoon beyond, one that the galley, with her shallow draught, could take and that the Niobe could not.

Yet their courses had been converging from the start and now the galley was well within reach of the nine-pounders. 'Pass the word for the gunner,' he said, and when the gunner came, 'Mr Borrell, I dare say you have the bow-chasers cleared away?'

'Why, yes, sir,' said Mr Borrell reproachfully. 'This last glass and more.'

'Then put me a ball across her bows, Mr Borrell. But not too close, hey? Hey? Don't you touch her, whatever you do; those flimsy one-and-a-half inch plank affairs sink for a nothing. And all our eggs are in one basket.'

Mr Borrell had no intention of sinking five thousand purses, and his shockingly successful shot brought his heart into his mouth. The ball pitched six feet ahead of the galley, sending a great fountain of water over her deck. It did not induce her to bring to, but it did give her something else to think about. She instantly backed water with a great flurry of oars, jigged, and then made for Hatiba again, while the opening in the reef slid fast astern.

They raced on, now the one gaining, now the other; but the general advantage lay with the Niobe. The distance between them dwindled to point-blank range and less, and if the galley had not obviously been convinced that no one would fire into her she must have struck her colours long since to avoid destruction: but a vessel with a cargo too precious to sink could run all risks except that of being boarded.

There was nothing Jack Aubrey loved more than a chase at sea; yet for some little time now his blazing delight had dwindled - the old story of the shrinking horse again. A carping voice in the back of his mind asked why all this alarm at the sight of a Company's ship on her lawful occasions? Why was the inlet passed so easily? And although Crimson Breeches was perpetually running up and down the gangway between the rowers, thumping his staff and haranguing them, surely the galley's real speed did not correspond to the threshing labour of the oars? Something was not quite right. He had deceived too many enemies at sea to be easily misled himself; and when they were within musket-shot and a subdued cheering had already started on the forecastle his uneasiness was confirmed and wholly justified by the sight of an inconspicuous line running from the galley's stern into her strangely troubled wake. 'Mr Williamson, Mr Calamy,' he called, and the midshipmen came running, their faces all aglow. 'Do you know what a lame duck does?'