"It's a non-burnable gas," Tom quickly explained. "But come on. This may be our very chance. There seems to be something going on that may be in our favor." Indeed the captives could hear confused cries and the running to and fro of many feet. He made for the sawed panel, and, in another instant, had burst out and was through it, out into the passageway between the after and amidship cabins. His companions followed him. They looked into the rear cabin, or motor compartment, and a scene of confusion met their gaze. Two of the foreign men who had seized the ship lay stretched out on the floor near the humming machinery, which had been left to run itself. A look in the other direction, toward the main cabin, showed a group of the foreign spies bending over the inert body of La Foy, the Frenchman, stretched out on a couch. "What has happened?" cried Ned. "What does it all mean?' "The lightning!" exclaimed Tom. "The bolt that struck the ship has knocked out some of our enemies! Now is the time to attack them!" The Mars seemed to have passed completely through a narrow storm belt. She was now in a quiet atmosphere, though behind her could be seen the fitful play of lightning, and there could be heard the distant rumble of thunder. "Come on!" cried Tom. "We must act quickly, while they are demoralized! Come on!" His friends needed no further urging. Jerry Mound and the machinist rushed to the engine-room, to look after any of the enemy that might be there, while Tom, Ned and the others ran into the middle cabin. "Grab 'em! Tie 'em up!" cried Tom, for they had no weapons with which to make an attack. But none were needed. So stunned were the foreigners by the lightning bolt, which had miraculously passed our friends, and so unnerved by the striking down of La Foy, their leader, that they seemed like men half asleep. Before they could offer any resistance they were bound with the same ropes that had held our friends in bondage. That is, all but the big Frenchman himself. He seemed beyond the need of binding. Mound, the engineer, and his assistant, came hurrying in from the motor-room, followed by Koku. "We found him chained up," Jerry explained, as the big giant, freed from his captivity, rubbed his chafed wrists. "Are there any of the foreigners back there?' "Only those two knocked out by the lightning," the engineer explained. "We've made them secure. I see you've got things here in shape." "Yes," replied Tom. "And now to see where we are, and to get back home. Whew! But this has been a time! Koku, what happened to you?" "They no let anything happen. I be in chains all the while," the giant answered. "Jump on me before I can do anything!" "Well, you're out, now, and I think we'll have you stand guard over these men. The tables are turned, Koku."