“Clear the islands and head away southward as hard as you can go,” replied Alexis briefly. The excitement of the battle in which he had played such a terrible part had left Alan in just the frame of mind to listen to the project of a desperate adventure, such as he instinctively knew was now in his friend’s mind. Without hesitating further he went into the saloon, summoned the crew of the _Narwhal_, and said to them-- “Alexis and I have decided upon an enterprise which will end either in very great injury to our enemies or our own destruction. You have seen enough to-day to know that in the warfare we are engaged in there are only two choices: victory or destruction. We don’t want to take anyone against his will to what may be certain death. Those who care to go ashore may do so.” Not a man moved. An athletic sailor named George Cosmo, who held the post of chief engineer, saluted, and said briefly-- “We shall all go, sir. What are the orders?” “Get out of the harbour as fast as you can, and as soon as you are clear of the islands sink two fathoms, steer a straight course due south-east, and put her through the water as hard as she’ll go,” replied Alan. Cosmo saluted again, and left the room with his comrades to execute the order. “Now, my friend,” said Alan, turning to Alexis as soon as they were alone again, “what is your plan?” “Simply this,” replied Alexis. “Mount Terror, or at any rate the mouth of the submarine tunnel, is in round numbers three thousand geographical miles from here. Our speed is thirty miles an hour faster than that of Olga’s squadron. That means that even if they go back at once and at full speed we shall be there four or five hours before them. “They, I think, have had quite enough fighting for to-day, and I don’t believe they’ll attack the island again--first, because they know that they can’t take our sea defences by surprise, and, second, because they think the _Narwhal_ will remain on guard. “Either they will go off on a raiding expedition somewhere else with the air-ships--in which case we can’t follow them, for we don’t know where they’re going--or they will return to Mount Terror at an easy speed of fifty or sixty miles an hour. They will never dream that you and I will venture to attack the stronghold single-handed, and, therefore, that is just what I propose to do.” “That will be odds of about forty to one against the _Narwhal_,” replied Alan, somewhat gravely. “Unless we can destroy it completely before they get back. But go on. Let’s hear the rest. I don’t think you can propose anything too desperate for me now that I have really tasted the blood of the enemy.” “Well, what I propose is not to destroy the stronghold, simply because it would be impossible to do that by sea. I merely propose to get quietly into the tunnel, go to that narrow part about two miles from the entrance, fix a dozen torpedoes with time-fuses up against the roof of the tunnel, and then clear out into the open water.