Looney reappeared, and the first diver instantly went down to replace him. This business was for the divers a gamble with life and death, a losing lottery. If the charge were to explode prematurely it would be chance that would dictate who would happen to be down there with it at that moment. But surely it could not take long to move the charge a few yards along the bottom and into the right place. And down there, he hoped, the fire was creeping along the coils of the fuse, sandwiched tight between the two barrelheads. The philosophers had decided chat fuses were able to burn in the absence of air—unlike candles—because the nitre that permeated the cord supplied the same combustible substance that air supplied. It was a discovery that went close to solving the problem of life—a human being’s life went out like a candle’s in the absence of air. It might be reasonably expected soon that the discovery might be made as to how to maintain life without air.

Yet another dive. The fire was hurrying along the fuse. Clout had allowed enough for an hour’s burning—it must not be too little, obviously, but also it must not be too much, for the longer the keg was exposed to the water pressure the greater the chance of a weak point giving way and water seeping in. But Clout had pointed out that in that confined space between the barrelheads the heat would not be able to escape; it would grow hotter and hotter in there and the fuse would burn faster—the fire might even jump from one part of the coil to another. The rate of burning, in other words, was unpredictable.

The diver who had just appeared gave a sharp cry, in time to prevent the next one—Looney—from going down. An eager question and answer, and Looney turned to Hornblower with a waving of hands.

“Get that man on board,” ordered Hornblower. “Up anchor!”

A few strokes of the oars got the launch under weigh; the Ceylonese in the bows were chattering like sparrows at dawn.

“Back to the ship,” ordered Hornblower.

He would go straight on board without looking back once; he would not compromise his dignity by awaiting an explosion which might never come. The tiller was put over and the launch began her steady course towards Atropos.

And then it happened, while Hornblower’s back was turned to it. A sullen, muffed roar, not very loud, as if a gun had been fired in a distant cave. Hornblower swung round in his seat just in time to see a bulging wave overtake them, heaving up the stern of the launch. The stern sank and bow rose, the launch pitching violently, like a child’s toy boat in a tub. The water that surged round them was discoloured and dark. It was only for a few seconds that the violent commotion lasted, and then it passed on, leaving the launch rocking jerkily.

“She’s gone up, sir,” said Clout, quite unnecessarily.

The hands were chattering as much as the Ceylonese.

“Silence in the boat!” said Hornblower.

He was angry with himself because the unexpected sound had caused him to leap in his seat. He glowered at the men, and they fell into a hushed silence.

“Starboard your helm,” growled Hornblower. “Give way!”

The launch swung round and retraced its course towards the scene of the explosion, marked by a dirty patch of water. Half a dozen big bubbles rose to the surface and burst as he watched. Then something else came up, and something else, dead fish floating up to the surface, their white bellies gleaming under the sky. The launch passed one which was not quite dead; it was making feeble efforts, just perceptible, to right itself and descend again.

“Silence!” said Hornblower again—the irrepressible chatter had broken out again. “Easy!”

In silence the launch floated over the scene of the explosion. Dead fish, a stain, and nothing else. Nothing else at all. Hornblower felt a sick feeling of disappointment; there should be fragments from the wreck covering the surface, shattered bits of timber to show that the powder charge had done its work. The fact that there was none was proof that no gap had been blown in the wreck. His mind was racing into the future. Another charge with another flying fuse would have to be used, he supposed, and the most brutal threats would have to be employed towards the divers to make them put it into position. They had escaped the last explosion by not more than thirty seconds, he supposed, and they would be chary of running the risk again.

There was a bit of timber! No, it was the plank which had been used as a marker buoy.

“Haul in on that line,” said Hornblower to the man pulling stroke oar. There was only ten feet of line attached to the plank—the line had been broken at that point; so the explosion had effected something, at least. It was ironical that that was all—just a marker buoy torn loose.

“Put on another grapnel and line,” ordered Hornblower. They must still be close enough to the spot for the marker to be better than nothing.

Hornblower caught Looney’s eye; he seemed willing enough to all appearance. It would save time if an examination of the scant results were made now.

“Looney,” said Hornblower, and pointed overside. He had only to point a second time for Looney to nod his agreement and pull off his clothes again. As far as Hornblower could remember Looney had not yet made his daily quota of five dives yet. Looney inflated his chest and slipped in, and the launch lay drifting. The little waves that slapped against her sides had a different quality from usual; they had not even the small amount of system arising from the wind that agitated the surface—they seemed to come from all points at once. Hornblower realized that they were the last dying remnants of turbulence which the explosion had set up.

Up came Looney, his slender bundle of black hair bobbing beside his face. His white teeth showed in what might almost be thought to be a smile, except that of course he was gasping for breath. He struck out towards the launch saying something to his colleagues as he did so which set them off twittering volubly. Apparently the explosion which had torn the marker buoy loose had not driven it any distance from its position. They hauled Looney on board into the bows. The chattering went on; now Looney was making his way aft over the thwarts and between the men. He was rubbing something in a portion of his clothing as he came—something which he put into Hornblower’s hand with a broad grin. Something discshaped and heavy, tarnished, encrusted, and yet—and yet—

“God bless my soul,” said Hornblower.

It was a shilling; Hornblower could only stare at it, and turn it over in his fingers. Every eye in the boat was directed at it; the men were quick enough to guess even if they could not see it clearly. Someone started to cheer, and the others took it up. Hornblower looked down the boat at the grinning faces. Even Clout was waving his hat and yelling.

“Silence!” shouted Hornblower. “Mr. Clout, you ought to be ashamed of yourself.”

But the noise did not stop instantly as before; the men were too excited. But it died away at length, and the men waited. Hornblower had to think now about the next moves completely at a loss—this development had taken him by surprise and he had no idea for the moment what to do next. It would have to be anticlimax, he decided at last. For the recovery of the treasure fresh equipment would be necessary; that was certain. The divers had made nearly as many dives that day as they could. Moreover, McCullum must be informed of the results of the explosion and his decision heard regarding further steps. Hornblower even realized that there was no certainty that subsequent operations would be easy. One shilling did not make a quarter of a million sterling. There might be much further work necessary.

“Oars!” he snapped at the waiting men. The oarlooms clattered into the rowlocks and the men bent forward ready to pull. “Give way!”