"The other side," said the captain in a lowered voice, as they failed to find any trace of the imprisoned lieutenant where they were. They were crossing a short gallery when Slim abruptly signaled a halt. "I thought I heard something," he said. "It sounded like another call." They stood silent a moment, and then, faint and indistinct, apparently from somewhere several feet ahead of them, they both heard repeated that which had made Slim stop. As the letters were tapped off upon the pipe the lad repeated them for the information of the captain. "S-M-O-T-H-E-R-I-N-G." "Smothering!" echoed the commander of the ship. "Great Scott! I believe I know now where he is. This way," and he started down the passageway toward a narrow stairs leading to a still lower chamber in the vessel. Three turns--two to the right and one to the left--and the captain stopped again to listen. Seemingly from within the wall, right at their elbows, there came a feeble knock. The officer whipped out a pocket flashlight. They were directly in front of a heavy wooden door. It was locked. "Run get a cold chisel or a heavy screwdriver and hammer," the captain ordered, and Slim hastened away, to return two minutes later with all three tools. "Stand back as far as you can from the door," said the captain, placing his lips close to the keyhole. But there was no response from within. Realizing now that Lieutenant Mackinson must have lost consciousness, and that moments might mean life or death to him, the captain worked with feverish haste. He drove the heavy chisel into the crack between the door and the jam, and then, standing off to get a wider swing with the hammer, struck it sidewise. A panel of the door cracked and loosened. Two more attempts and the panel fell in strips to the floor. Thus given something for a grip-hold, the captain, who was a massive man, took hold with both hands, put his right foot against the wall, and, with one tremendous tug, into which he threw the whole weight of his body, brought the entire door from its hinges. The captain went staggering backward from the force of his effort and the weight of the door. The unconscious form of Lieutenant Mackinson tumbled out upon the floor. His face was almost blue from suffocation. The captain sounded three short, sharp blasts upon a whistle which he had taken from his pocket, and two oilers came running to the spot. "Help us carry this man to fresh air immediately," he ordered. "He has been overcome." With one of the oilers carrying the lieutenant by the feet, and the other man and Slim at either shoulder, the unconscious young officer was carried up flight after flight of steps until, the captain leading the way, they arrived at the promenade deck. A seaman was dispatched for the ship's surgeon, who arrived a few minutes later to find the first-aid efforts of the four men just bringing Lieutenant Mackinson back to consciousness.