All those people in the coaches behind him—most of them peacefully sleeping—stirred the young fellow’s thought. He had pulled a Class-A passenger train before this night—many times, in fact—and had felt something of the same oppression of responsibility; but this case seemed particularly important. Thick forest hid the bottom of the valley. When he glanced down he could see the pale moon silvering the tops of the firs and larches. The express seemed plunging into a vast and bottomless pool of black water. He began to pull down for the curve at the bottom of the grade. This was always a dangerous point. Once, years before, Ralph had seen the wreck of the head-end of a freight piled up at the foot of this cliff, which overhung the right-of-way. Since that time the engineers of the Great Northern had broken off the granite overhang of the cliff above this spot and had seemingly made a repetition of that accident impossible. Yet an enemy of the road might place some obstruction on the track just below the curve. Until the head of the locomotive was right at the turn, Ralph could not see what was ahead. The road should have kept a signalman at this point, day and night. Never before had the young fellow so understood the weight of responsibility that rested on the engine driver’s shoulders. Perhaps it was because he was growing older. Or perhaps the recent sad happening to old Byron Marks had made a deep impression on Ralph Fairbanks’ mind. At any rate, he felt that he would never round this curve again—or any other blind curve on the division—without experiencing a tremor of fear. Suddenly a figure leaped into view, silhouetted against the silver tree tops beyond and behind it, not on the dangerous side of the rails. It stood upon a high bowlder across the right-hand ditch. A tall, ghostly figure, the appearance of which made Ralph reach for the reverse lever with nervously crooked fingers. Then he realized that it was some person who signalled “All clear” with arms like those of a semaphore. Somebody then was on watch here at this dangerous turn. Ralph applied the brakes carefully, gently. The long train shuddered; but there was no harsh jouncing of the coaches. The wheels slid around the turn. And as the ray of the headlight caught the figure on the bowlder for a moment, the young railroader knew who it was. “Zeph!” he ejaculated, under his breath. The young assistant of Bob Adair had selected the most perilous point in Shadow Valley to watch. While Zeph was there, Ralph might be pretty sure that no harm would befall the division trains. He was carried past the bowlder swiftly. He leaned out to wave his arm and try to attract the notice of his friend. But the flash of the headlight’s ray had undoubtedly blinded Zeph for the moment and there was no answering signal from him. However, as long as Zeph was faithful at that post Ralph would feel little anxiety in approaching it.