"You--surely, you wouldn't do that!" ejaculated the major, startled. His rubicund face grew round with amazement. "That remains to be seen. Come, let's have a look at him!" Together they went out into the brightly lighted main corridor, near the ladder to the upper gallery, turned to the right and walked aft. A door, just a little abaft the chartroom and, opposite the Master's cabin, gave a glimpse of the as yet unoccupied smoke-room. Astern of this, they passed the dining-saloon with its long table and its swivel-chairs. Beyond several stateroom doors they came to the transverse corridor at the other side of which, directly facing the main corridor, the engine-room door opened. Entering the engine-room, they found themselves in a brightly lighted compartment fifteen feet wide by twenty-six feet, seven inches long. This compartment contained six Norcross-Brail engines, each capable of developing 1,150 H.P. The engines were in charge of Auchincloss and two assistant engineers, who had all six engines filling the room with a drowsy drone, like ten billion bees humming themselves to sleep in some mysterious hive. So nicely adjusted was every part, so accurately true was every shaft, bearing, gear, that practically no vibration could be noted. The voice, in ordinary tones, carried perfectly; and yet in that small space nearly 7,000 H.P. were being produced and transmitted to the propellers and to the storage batteries that operated helicopters and compressed-air system, as well as the lighting-plant of the air-liner. As the two men entered the engine-room, the Master nodded to Auchincloss. He stood a moment gazing at the brightly flecked metal of the engines, the gleaming walls--hollow and filled with noninflammable helium gas of great lifting power--the men on watch over all this splendid mechanism. Then he passed between engines No. 4 and No. 5, toward the aft wall of the compartment. Four doors opened in the bulkhead, there. Two communicated with storerooms, one opened into the passage that led to the aft observation pit, the fourth gave access to the sick-bay. This door the Master slid back. Followed by the major he passed through. A small but fully equipped hospital met their eyes. Cots, operating-table, instrument-cases, sterilizers, everything was complete. Immaculate cleanliness reigned. On two of the cots, men were lying. Beyond, Captain Alden--still fully dressed--was sitting on a white metal chair. The captain's face was still concealed by the celluloid mask, but a profound pallor was visible on the lower portion of his right cheek and along his left jaw. The set of that jaw showed an invincible obstinacy that bespoke rebellion.