"There it goes at last!" exclaimed Natasha, as the last of the level beams shot across the cloud-sea and the rim of the pale disc sank below the surface of the vapoury ocean. "The time that we have waited and worked for so long has come at last. This is the eve of Armageddon! Who would think it, floating up here above the clouds and beneath those cold, calmly shining stars! And yet the fate of the whole world is trembling in the balance, and the doings of the next twenty-four hours will settle the destiny of mankind for generations to come. The hour of the Revolution has struck at last"-- "And therefore it is time that the Angel of the Revolution should give the last signal with her own hand!" said Arnold, seized with a sudden fancy, "Come, you shall start the dynamo yourself." "Yes I will, and, I hope, kindle a flame that shall purge the earth of tyranny and oppression for ever. Richard, what must my father be thinking of just now down yonder in the cabin?" "I dare not even guess. To-morrow or the next day will be the day of reckoning, and then God help those of whom he demands payment, for they will need it. The vials of wrath are full, and before long the oppressors of the earth will have drained them to the dregs. Come, it is time we went down." They descended together to the engine-room, and meanwhile the air-ship sank through the clouds until the lights of Aberdeen lay about a thousand feet below. A lens of red glass had been fitted to the searchlight of the _Ithuriel_, and all that was necessary was to connect the forward engine with the dynamo. Arnold put Natasha's hand on a little lever. As she took hold of it she thought with a shudder of the mighty forces of destruction which her next movement would let loose. Then she thought of all that those nearest and dearest to her had suffered at the hands of Russian despotism, and of all the nameless horrors of the rule whose death-signal she was about to give. As she did so her grip tightened on the lever, and when Arnold, having given his orders to the head engineer as to speed and course, put his hand on her shoulder and said, "Now!" she pulled it back with a sharp, determined motion, and the next instant a broad fan of blood-red light shot over the _Ithuriel's_ bows. At the same moment the air-ship's propellers began to spin round, and then with the flood of red light streaming in front of her, she headed southward at full speed towards Edinburgh. The signal flashed over the Scottish capital, and then the _Ithuriel_ swerved round to the westward.