“After a search of five hours, the search-lights of the boat revealed a huge tunnel leading south-west into the land, that is to say, direct for Mount Terror. They followed this tunnel up for a distance of nearly five miles, and then struck the end. They now rose, and finally found themselves floating on the surface of the lake in the interior of the mountain.
“One of Kishenov’s officers, a man named Louis Khemski, was a member of the Russian Revolutionary Society, whose existence only became known five years ago. After the capture of the Ithuriel the heads of this society met, and to them this man communicated the secret of Mount Terror. Kishenov and the other officer refused to join the revolutionists, and were assassinated.
“Khemski was at once taken on board the Ithuriel, now renamed the Revenge, and guided her to the fissure leading into Mount Terror. Its outer portion was of course filled and covered with ice and snow, but as soon as Khemski had found its position by his landmarks, a couple of shells speedily reopened it, and it was here that the Revenge lay hidden while you were ransacking the world for her.
“Olga inherited from her grandfather, the father of the Vladimir Romanoff who was executed for disobeying the order of the Council, all the plans and directions necessary for the building both of air-ships and submarine vessels, and as soon as this perfect stronghold and hiding-place was discovered, her accomplices in the conspiracy for the restoration of the Russian monarchy at once devoted their fortunes to the supply of money and materials. The Revenge made one more voyage to Russia, and by travelling at full speed at a great elevation managed to make it unobserved.
“The services of the cleverest engineers and most skilful craftsmen among the revolutionists were secured. Transports were chartered and sent out to Antarctica loaded with materials. On the shores of the subterranean lake the first squadron of submarine vessels was built, and then began the system of ocean terrorism which soon paralysed the trade of the world.
“Piracy was carried on with utter ruthlessness. Transports were sunk by the vessels, and then plundered by divers of the treasure which they carried, and which was employed to purchase new materials and to repay those who had furnished the first funds.
“Alexis and myself were kept by Olga, as I said in my first letter, under the influence of a drug which completely paralysed our volitional power, and were compelled to reveal all we knew concerning our own air-ships, submarine vessels, guns, and explosives. And in this manner was created and equipped the force which will be employed to dispute with us the empire of the world unless we are able to extirpate it utterly.”
While the despatch to the Council was being drawn up, the Narwhal had been lying in the inner basin of Christmas Harbour, renewing her store of motive power from the generating station ashore. As soon as the engineer in charge reported that her power-reservoirs were full, and Alan had delivered the despatch for conveyance to Aeria by air-ship, Alexis, who had been apparently buried in a brown study for the last two hours or so, asked Alan to come with him into his private cabin, and as soon as the two friends were alone together he said to him—
“Look here, old man! While you fellows have been drawing up that despatch, and talking about the impossibility of attacking the stronghold at Mount Terror, I’ve been doing some thinking, and I’ve come to the conclusion that as far as an under-sea attack is concerned, it isn’t quite so hopeless as you’ve made out.”