'After that nothing happened for quite a while. Then the pitch of the humming that we'd got so used to that we didn't notice it began to change so that we did notice it. The boffin beside me gave a grunt and whipped back like a streak into a kind of float-off instrument-room they had rigged up on deck. You could feel a sort of trembling in the deck, and the humming kept on changing pitch, and everybody gave a hitch to his life-jacket, and got ready for something to happen.
'The thing that did happen was that Number Three dolphin way ahead of us blew up. It was a far smaller blow than the others had been, and they reckon it was just the vibrations that set her off. She certainly didn't go for anything. The hailer started to order out Number Four dolphin, and in the middle of that an excited boffin bounced out of the instrument-room and ordered the depth-charge-thrower to work. It lobbed off a couple of spherical containers which just sank. We kept on waiting for a couple of bangs until we realized that they weren't going to come. And that was roughly that.
'After a bit the humming settled down to what it had been before, and there was a noise of uproarious boffins slapping one another on the back in the instrument-room.
'We altered course to the north. About an hour later Number Four dolphin went up with a thundering good wham. The boffins, all of them pretty tight by this time, tumbled out on deck to cheer and sing Steamboat Bill, and that was about the end of it. We still had Number Five dolphin running serenely ahead of us when we reckoned we were clear of the area.'
A nice lad, Lieutenant Royde, but not, perhaps, a source of technical information. However, it was eye-witness stuff we were after. We knew in a general way how the 'dolphins' worked, and we had heard that the spheres launched by the mine-thrower were intended to home on the source of the vibrations, and were capable of reaching far greater depths than the dolphins. Even if it had been explained to us exactly how they did it we should probably not have understood.
The effects of the successful tests were immediate. There was an overwhelming demand for the defensive gear, and shipping shares began to rally. Freights, however, remained high. There was the cost of the gear to be covered, consumption of dolphins to be offset, and it would take some time before all cargo vessels could be equipped and revert to their normal courses. Meanwhile, the price of everything went up.
Progress in equipment was such, however, that six months later it was possible for London and Washington to speak optimistically. The Prime Minister announced to the House:
'The Battle of the Deeps has been won. Our ships, which we had to divert, are able once more to ply upon their usual courses.
'But we have seen before, and we must remember, that to win a battle is not of necessity to win a war. These menaces that have for a time played the highwayman upon our vital sea-lanes and caused us such grievous losses, these menaces still remain. And, as long as they remain, they are a potential danger.
'We cannot afford, therefore, any slackening of effort in combating them. We must use all our capacities and our wits to find out more, everything we can, about this peril that is lurking beneath our seas. For still, and in spite of the fact that we have won this battle, we know virtually nothing of it, save that it exists. No one no one can describe these creatures if creatures they are; no one, so far as we know, has ever seen them. To us, here in the sunlight, these creatures of the darkness and the depths, are still, anonymously and amorphously, "those things down there".
'When we know more about them, their nature, their strength, and, most importantly, their weaknesses: when, in fact, we have a full view of what we are about, then we shall be able to launch our attack upon this pestilence so that, with its utter destruction, our ships and our seamen shall be free to sail upon the high seas of the world facing only such perils as their gallant fathers faced before them.'
But, a month later, a dozen ships of various sizes were sunk in a week, four of them while attempting to rescue survivors of earlier disasters. The few men who were brought safely back could tell little, but from their accounts it appeared that the dolphins had operated successfully; the other gear for some reason had failed to prevent the ships shaking to pieces under their feet.
Official advice once more recommended that the neighbourhoods of all the greater Deeps should be avoided pending further investigations.
Hard on that, but with a significance that was not immediately recognized, came the news first from Saphira, and then from April Island.
Saphira, a Brazilian island in the Atlantic, lies a little south of the Equator and some four hundred miles south-east of the larger island of Fernando de Noronha. In that isolated spot a population of a hundred or so lived in primitive conditions, largely on its own produce, content to get along in its own way, and little interested in the rest of the world. It is said that the original settlers were a small party who, arriving on account of a shipwreck some time in the eighteenth century, remained perforce. By the time they were discovered they had settled to the island life and already become interestingly inbred. In due course, and without knowing or caring much about it, they had ceased to be Portuguese and become technically Brazilian citizens, and a token connexion with their foster-mother country was maintained by a ship which called at roughly six-monthly intervals to do a little barter.
Normally, the visiting ship had only to sound its siren, and the Saphirans would come hurrying out of their cottages down to the minute quay where their few fishing boats lay, to form a reception committee which included almost the entire population. On this occasion, however, the hoot of the siren echoed emptily back and forth in the little bay, and set the sea-birds wheeling in flocks, but no Saphiran appeared at the cottage doors. The ship hooted again, but still there was no sign of anyone making for the quay. There was no response whatever, save from the sea-birds.
The coast of Saphira slopes steeply. The ship was able to approach to within a cable's length of the shore, but there was nobody to be seen nor, still more ominously, was there any trace of smoke from the cottages' chimneys.
A boat was lowered and a party, with the mate in charge, rowed ashore. They made fast to a ringbolt and climbed the stone steps up to the little quay. They stood there in a bunch, listening and wondering. There was not a sound to be heard but the cry of the sea-birds and the lapping of the water.
'Must've made off, the lot of 'em. Their boats's gone,' said one of the sailors, uneasily.
'Huh,' said the mate. He took a deep breath, and gave a mighty hail, as though he had greater faith in his own lungs than in the ship's siren.
They listened for an answer, but none came, save the sound of the mate's voice echoing faintly back to them across the bay.
'Huh,' said the mate again. 'Better take a look.'
The uneasiness which had come over the party kept them together. They followed him in a bunch as he strode towards the nearest of the small, stone-built cottages. The door was standing half-open. He pushed it back.
'Phew!' he said.
Several putrid fish decomposing on a dish accounted for the smell. Otherwise the place was tidy and, by Saphiran standards, reasonably clean. There were no signs of disorder or hasty packing-up. In the inner room the beds were made up, ready to be slept in. The occupant might have been gone only a matter of a few hours, but for the fish and the lack of warmth in the turf-fire ashes.
In the second and third cottages there was the same air of unpremeditated absence. In the fourth they found a dead baby in its cradle in the inner room. The party returned to the ship, puzzled and subdued.
The situation was reported by radio to Rio. Rio in its reply suggested a thorough search of the island. The crew started on the task with reluctance and a tendency to keep in close groups, but, as nothing fearsome revealed itself, gradually gained confidence.