The dog, meanwhile, had passed through the crazily splintered doorway and had paused on the threshold of the improvised hospital, as the reek of iodoform and of carbolic smote upon his sensitive nostrils. In front of him was the stone-paved vestibule. Beyond was the interior of the shattered church, lined now with double rows of cots. Seated on a camp-chair in the shadowy vestibule was the pseudo Red Cross nurse. At sight of the collie the nurse got up in some haste. Bruce, still walking stiff-legged, drew closer. Out from under the white skirt flashed a capable and solidly-shod foot. In a swinging kick, the foot let drive at the oncoming dog. Before Bruce could dodge or could so much as guess what was coming,--the kick smote him with agonizing force, square on the shoulder. To a spirited collie, a kick carries more than the mere pain of its inflicting. It is a grossly unforgivable affront as well--as many a tramp and thief have learned, at high cost. By the time the kick had fairly landed, Bruce had recovered from his instant of incredulous surprise; and with lightning swiftness he hurled himself at his assailant. No bark or growl heralded the murderous throatlunge. It was all the more terrible for the noiselessness wherewith it was delivered. The masquerading man saw it coming, just too late to guard against it. He lurched backward, belatedly throwing both hands up to defend his throat. It was the involuntary backward step which saved his jugular. For his heel caught in the hem of his white skirt. And wholly off balance, he pitched headlong to the floor. This jerky shift of position, on the part of the foe, spoiled Bruce's aim. His fearful jaws snapped together harmlessly in empty air at a spot where, a fraction of a second earlier, the other's throat had been. Down crashed the disguised man. And atop of him the furious dog hurled himself, seeking a second time the throatgrip he had so narrowly missed. At this point on the program Sergeant Mahan arrived just in time to bury both hands in the mass of Bruce's furry ruff and to drag the snarlingly rabid dog back from his prey. The place was in an uproar. Nurses and doctors came rushing out into the vestibule; sick and wounded men sat up on their cots and eagerly craned their necks to catch sight of the scrimmage. Soldiers ran in from the street. Strong as he was, Mahan had both hands full in holding the frantic Bruce back from his enemy. Under the insult of the kick from this masquerader, whom he had already recognized as a foe, the collie had temporarily lost every vestige of his stately dignity. He was for the moment merely a wild beast, seeking revenge for a brutal injury. He writhed and fought in Mahan's grasp. Never once did he seek to attack the struggling man who held him. But he strained every giant sinew to get at the foe who had kicked him.