After four hours a small car bearing the license number of a distant state--which was found, by subsequent telegraphing, to be unknown to the authorities of that state--drove under the porte-cochere, and the hidden watcher saw DuQuesne, without the papers, step into it. Knowing now what to expect, Prescott drove his racing motorcycle at full speed out to the Park Road Bridge and concealed himself beneath the structure, in a position commanding a view of the concrete abutment through which the scientist must have come. Soon he heard a car slow down overhead, heard a few rapid footfalls, and saw the dark form of a large man outlined against the gray face of the abutment. He saw the man lift his hand high above his head, and saw a black rectangle appear in the gray, engulf the man, and disappear. After a few minutes he approached the abutment and searched its face with the help of his flash-light. He finally succeeded in tracing the almost imperceptible crack which outlined the door, and the concealed button which DuQuesne had pressed to open it. He did not press the button, as it might be connected to an alarm. Deep in thought, he mounted his motorcycle and made his way to his home to get a few hours of sleep before reporting to Crane whom he was scheduled to see at breakfast next morning. * * * * * Both men were waiting for him when he appeared, and he noticed with pleasure that Shiro, with a heavily-bandaged head, was insisting that he was perfectly able to wait on the table instead of breakfasting in bed. He calmly proceeded to serve breakfast in spite of Crane's remonstrances, having ceremoniously ordered out of the kitchen the colored man who had been secured to take his place. "Well, gentlemen," the detective began, "part of the mystery is straightened out. I was entirely wrong, and each of you were partly right. It was DuQuesne, in all probability. It is equally probable that a great company--in this case the World Steel Corporation--is backing him, though I don't believe there is a ghost of a show of ever being able to prove it in law. Your 'object-compass' did the trick." He narrated all the events of the previous night. "I'd like to send him to the chair for this job," said Seaton with rising anger. "We ought to shoot him anyway, damn him--I'm sorry duels have gone out of fashion, for I can't shoot him off-hand, the way things are now--I sure wish I could."