"It is very far from nonsense." Miller's earnestness impressed Whitney. "I do not for one moment believe that Spencer was working alone." "You hint at conspiracy?" Whitney frowned perplexedly. "Call it that if you wish; only, sir, take every precaution to safeguard your inventions from prying eyes." "I have, already." "How, for instance?" "With double locks, iron shutters, and electric wires, my workshop is hermetically sealed." "Until a clever thief gains entrance." Miller laughed faintly. "The science of house-breaking keeps step with modern inventions to protect property. What one man can conceive another man can fathom." "You may be right." Whitney took a short turn about the room, then stopped in front of his companion. "What precautions would you suggest?" Miller did not answer immediately. "It is very likely that another attempt will be made to secure the drawings and specifications of your inventions, if not your models," he said finally. "And if on guard, you may not only catch the thief but Spencer's murderer." "A good idea," acknowledged Whitney. "But how would you suggest going about to catch the thief?" "By laying a plot for him; forget to lock your studio door occasionally, lay prepared paper inconspicuously about, and powder your tables and floor with fine dust. The thief will leave an indelible trail behind him." "And walk off with all necessary data," answered Whitney skeptically. "As clever a thief as you paint will never leave that room, once he is inside it, without full knowledge of my inventions." "The thief will not have an opportunity of stealing what he came for, because the specifications and drawings of your inventions will not be there." "Eh!" Whitney's cigar fell unheeded to the floor. "Where will they be?" "In my possession." Too astounded to speak, Whitney stared at his companion. It was over a minute before he recovered himself. "Do you think I will trust you with the drawings and models of my latest inventions?" he asked. "You did not withhold your consent when, a short time ago, I asked for Kathleen's hand in marriage," said Miller slowly. "Do you hold your inventions dearer than your daughter's future happiness, which you are willing to intrust to my care?" Never taking his eyes from his companion's face Whitney stepped back. The seconds lengthened into minutes before he spoke. "Come upstairs," he said and, turning, made for the closed door. CHAPTER XIX THE YELLOW STREAK