“Look at my hand,” said David absently. A broad purple stain spread across the palm. “How did you get that?” asked Red. “It’s indelible lead. I must have spilled some leads out of my suitcase when I was turning over things to find that envelope. I was on my hands and knees, and must have pressed my hand down pretty hard. My palm was moist, and the darned thing spread the way it always does. Beastly stuff! It won’t wash off.” “Mechanic’s paste ought to fix it,” said Red. “Where is the pencil?” “Clipped to my lost notebook. ‘Anyone returning plans may keep pencil, and no questions asked’,” David said ruefully. Things went badly all that day. The ship lagged along in a head wind, all five engines going at top speed, every engineer at his post. It was generally known, now, that David had no copy of the lost plans. So the thief could make the invention public under the name of an accomplice. Mr. Hammond stayed in the chart room, watching the indicator as it ruthlessly registered the speed of the ship, the conviction growing steadily that they would never be able to beat the record of their great predecessor, the Graf Zeppelin. David hovered over the wheel. He was sick at heart. Little things bothered him. The blue stain on the palm of his hand annoyed him. The mechanic’s paste had not worked very well. After luncheon Mr. Hammond instituted another search for the missing plans, but in vain. Just one more night, and they would reach Los Angeles, and the plans would walk off for good. Mr. Hammond decided to search every man before he left the ship. When afternoon tea was served, Dulcie coaxed David from the control room. “You haven’t spoken to me for days,” she said. “I’m rather upset, Dulcie,” he replied, “and pretty poor company.” “You are always good company, Davie,” she said, comfortingly. “Some good hot tea will pep you up. Cakes?” David sipped his tea in silence. “I wish you wouldn’t worry,” Dulcie said presently. “Dad thinks he can advertise it so the thief won’t dare to use your plans at all.” “That won’t work, Dulcie. You see, every scratch I had ever made on the subject was in that envelope, and it would only be my word against his.” “Couldn’t Red swear he had seen it?” “Yes, and then some pals of the thief could swear that they had actually helped construct it.” “Dad’s going to search every man as he gets off the ship at Los Angeles.” “What’s to keep him from weighting it, and tossing it out of the ship some good place outside the city? He could easily go back for it.” “My word, David, what an awful thought!” “I think the plans are gone for good, Dulcie, but if they are, I’m not going to crab over it. My luck holds yet. Nothing can ever take away from me the fact that I have been captain of the Moonbeam. I have learned a lot, and I have made some good friends.” “I come in there, Davie,” said Dulcie decidedly.