there was no need that they should

  It was certain, therefore, that the danger lay in front, where the forest across the grade, and the elevation of the grade itself, protected the besiegers. The bohunks would be slow to expose themselves. Indeed, there was no need that they should, since escape was impossible. Not only was there nowhere to flee, but without its defenders the trestle would be at the mercy of the I.W.W.   Mahon did not trouble to speculate as to the end of the affair. His duty was to fight to the last, to protect life first and then the work of the contractors. Only when he remembered Tressa did his thoughts pass beyond the immediate future. Fortunately his wife, alone three miles away, did not enter his mind as a matter for anxiety.   Arrived within a stone's throw of the shack, and having heard no sound, he knew that his conclusions as to the disposition of the bohunks were correct. Swinging out wide of the grade, he skirted about in the darkness in search of isolated prowlers. The stable was reached without incident.   The late moon was rising, low still but clear enough to throw a dim light and touch the tops of the evergreen trees with a cold radiance so wild and pure that Mahon found it hard to believe in the perils urging him on. In an hour the light would be strong enough to expose movement within the danger zone, though the size of the moon and a thin autumn mist limited it; and the low arc promised long shadows. Far to the south drifted the running echo of coyotes on the hunt, a shriek and a howl that never failed to stir the Sergeant's blood though he had lived with it for years. For a moment he longed for the old prairie life--the coyotes--the feeding cattle--the cowboys and the sweeping open spaces.