He smiled bitterly. It seemed impossible for anyone to expect anything important could be accomplished by little Manool Sarouk. Well, if things went right, he was certainly going to show them, this time. In spite of his haste, and in spite of the fact that Rogers helped him after the third trip, it was some little time before Manool dropped down in the tank-room after that last box. He heaved a huge sigh of relief as he put it into the ventilator shaft, and turned to do the one thing left to do. This was the one job he hated, but it was the most important job of all. He went to his locker and got out a big bottle and poured liquid from it into every one of the tanks. He turned off a valve under each tank and took a hammer and beat the valve-handle into uselessness. Then, after checking to make sure he hadn't overlooked anything, he climbed into the tube and started pushing that last box of tooth-powder ahead of him. At last he reached the mess-room again and handed down his box. He climbed down, himself, and had no more than landed when Tarrant was on him with a whispered, "Come on now, Manool, tell us what this is all about." "Just a couple minutes more, Captain," Manool pleaded. "You think they can get through that door?" "Not a chance," Rogers spoke up. "That's fine. Maybe, then, you help me fix that ventilator, too." They put the grill back on the ventilator, and covered it by nailing boards from the table over it. "By-'n'by, we make that air-tight," said Manool, and gave his next order. Yes, he was giving orders to the captain and the navigator now, and he was quite conscious that he was doing so. "You get all the bowls and pans and pots in here and fill 'em with water. No telling when those fellows decide to cut our water lines." It took them half an hour to do that, and it wasn't until it was done that Manool felt satisfied. Then he began to break open one of the cartons of tooth-powder, explaining his plans as he did so, in the same whisper he had used all along. "Those fellows out there got the whole ship to themselves," he said. "They got lots of food and lots of water and lots of air. They got fuel, too, and somebody who can lay an orbit for contact with Ceres. But I don't think they ever get there. "There's a whole lot of fellows, too," said Manool, dubiously. "I think maybe the air they got won't last 'em." "Their _air_!" ejaculated Tarrant. "Manool, you haven't monkeyed with the tanks, have you?" "I just kill the water-weed, that's all." "Are you nuts, little man?" asked Tarrant at last. "How in thunder are _we_ going to breathe, when this air gets stale. You may smother those pirates, but we're all in the same boat here, you know." Manool smacked his fist into his hand to emphasize his remark. "We may be in same boat, but we three, we're in different part of this boat. Maybe them rats outside quit breathing, all right, but not us! Look here."