So Olga was at last convinced that her choice lay between abandonment of the attack or running the gauntlet of fire in the almost forlorn hope of engaging the land batteries and an aerial fleet of unknown strength at close quarters.

Baffled and defeated, and yet convinced that to continue the unequal contest under its present conditions would be merely to court still more disastrous defeat, and even probable destruction, Olga at last allowed Lossenski to give the signal for retreat, and the Russian squadron withdrew to a position twelve miles northward of the island. Its departure was seen both from the air and the land, and the cannonade immediately stopped.

Meanwhile Alan had run the Narwhal into the mouth of Christmas Harbour flying his red flag. He was met by the Cachalot, and, after telling Captain Ernstein what he had done, and learning of the repulse of the Russians in the aerial battle, he directed forty of the submarine vessels to follow him out to sea to look for the Russian flotilla.

All the craft were furnished with tell-tale needles similar to the one on board the Narwhal, for it is impossible to see a sufficient distance under water to effectively attack an enemy as agile as the submarine warships were, and this fact had led to the universal employment of the needles.

As it was now quite light, the whole Aerian squadron, with the exception of five vessels whose duty it was to act as scouts under water, proceeded seaward on the surface of the waves, keeping a sharp look-out for the remains of the Russian fleet, which they soon discovered lying about five miles off the island. They could make out thirty-five of the long, black, half-submerged hulls lying together like a school of whales with the waves breaking over them as over sunken rocks.

Alan immediately signalled from his conning-tower in the manual sign-language, used by the Aerians to communicate between their air-ships, to his consorts, and ordered them to scatter and form a wide circle round the Russian squadron at a distance of a mile, and a depth of two fathoms, but on no account to approach within a thousand yards of them. When they had reached their positions they were to rise to the surface and each was to discharge a couple of torpedoes towards the centre of the circle. After that they were to retire and leave the rest to him.

The moment the order had been passed through the fleet, everyone of the vessels disappeared and proceeded to her station. The Narwhal sank at the same time until nothing but the glass dome of her conning-tower remained above the water.

By carefully noting the course steered by the compass, and accurately measuring the distance travelled by the number of revolutions of the propeller, each captain was able to place his craft in the desired position.