"Halt! Notify them from where you are. I shall not permit you to go any farther." All the men were found to be stationed near the hatchway steps. One by one they appeared, and were escorted out, a dozen marines in the meantime having appeared in two boats. As they emerged from the door they were escorted to the side and directed to take their places in the ship's boats. "That makes twenty-one," said Alfred. CHAPTER X THE SECRET KEY TO THE BOMB FUSE "Shall I go down and assist in bringing up the lieutenant?" said the sub-lieutenant, as the doctor of the submarine passed out. "No; I have decided that he shall not be removed until this evening," said the captain. "In the meantime the doctor may return, and give him such aid as is necessary." The sub-lieutenant's face turned pale, and he trembled. This was the first show of weakness that he exhibited. The boys looked at the captain, and turned their glances toward the officer of the chaser. They could not understand it. The captain continued: "I believe the chief machinist is also injured, as well as two of the machine tenders. They may also remain until after the lieutenant is brought up." All present noticed the wrought-up condition of the sub-lieutenant, and the latter soon exhibited evidence that he was breaking down. At last he remarked with trembling voice: "At what time can they be brought up?" "I cannot tell at this time; possibly not until tomorrow," said the captain, directing a searching glance at the officer. "He is very ill," said the doctor. "I have no doubt of it," replied the captain. "The length of their stay in the submarine will depend on the length of the fuse attached to the time explosive in the hold." The sub-lieutenant almost dropped as the captain uttered these words, and the boys exchanged significant glances, while the lieutenant of the chaser smiled. "You did not think," continued the captain, "that I would be so lax in my duty as to permit you to plant a mine under our feet?" The sub-lieutenant dropped his eyes without answering. The captain gazed at him intently, as he continued: "For the present you will be detained, and the time of the removal of the lieutenant with his companions will be decided within the next two hours." With this decision the sub-lieutenant was put in charge of the marines, while he descended to enter the boat. As he was about to step aboard, he turned to the captain and said: "It will be too late if you defer the decision for two hours." "Ah!" said the captain with a faint smile, "you have thought better of it. Will the fuse last an hour?" The sub-lieutenant nodded. The captain waved his arms and directed the officer to proceed. The latter unceremoniously pushed the sub-lieutenant into the boat. "I will see to it that the fuses are taken out," said the sub-lieutenant, recovering from his sullen attitude.