"A machine has stopped here at the side of the road quite recently," Mr. Peck offered, pointing to the tire marks in the dust. "The occupant, as is indicated by those very clear foot prints, stepped from the car, crossed the ditch and walked to the railroad tracks. He was a heavy man, at that, or at least he has big feet. And they turn out more than the feet of the average person." Charlie Ward nodded agreement. "Now if you'll look closely," Mr. Peck went on, "you will observe that there are two sets of foot prints; one coming and one going. The return prints, significantly, are not as clear as those that go to the tracks, indicating that he was carrying a load to the tracks, but did not return with it." He glanced at Ward for a moment, then added, "It is pretty obvious what that load was. All of which gives us practically undeniable proof that a murder was committed. The deceased died of poison. We have definitely established that point. And his body was placed upon the tracks to conceal the fact; or to attempt to do so. If the deceased had walked to the tracks himself, which of course he didn't because these are not his foot prints, there obviously would be no return prints. Dead men, especially decapitated dead men, seldom, if ever, retrace their steps." He paused for a moment of conjecture. "We'll take plaster casts of the foot prints as well as the tire marks. Will you attend to that Christian? I believe you'll find sufficient plaster of Paris in the tool compartment." Christian set to work and Mr. Peck and Ward retreated to the machine. When Christian had completed his work, the trio returned to headquarters, Mr. Peck leaving again to "do a little thinking." Two hours later, Mr. Peck entered Charlie Ward's office again and eased himself into a chair. "I have an idea," he informed Ward, "that the apprehension of the murderer is but a matter of moments. As a matter of fact, I can put my finger on him in ten minutes should I care to." "You can put your finger on him right this minute if you want to," Ward supplemented, taking his feet off the desk and flipping a cigarette butt through the window. "How so?" Ward unlocked a drawer in his desk and drew out a tin box from which he produced a thickly padded envelope. "I been doing a little scientific snooping myself," he announced with a proud ear to ear grin. "That's extremely gratifying." Ward thumbed toward a cigar butt in an ash tray. "That," he said, "is what's left of a cigar you give me this morning. It gives off a pretty thick aroma." "It ought to. They cost me a dollar each." "Just take a whiff of this," Ward said, handing the envelope to Mr. Peck. The latter smelled cautiously. "Why, it smells like my cigars." "Exactly. Now take a squint in the envelope." Mr. Peck opened the envelope and extracted a sheaf of currency. "There's about twenty-four grand there," Ward offered.