Kilgore saw his flight cut off in that direction, but he knew every inch of the house. He turned like a rat in the darkness, and made for the stairs leading to the floor above. Up these he hurriedly scrambled. Nick heard him through the gloom, and followed him, pitching headlong at the foot of the stairs just as Kilgore opened the door leading to the hall above. There the dim rays from a hall lamp revealed the man for an instant, and showed Nick the way. He was up again and after Kilgore like a hound after a fox. Kilgore dashed through the hall, but dared not take time to unlock and open the front door of the house. He had a profound respect for the revolver in the hand of his pursuer, who already had reached the hall. It was a flight for life, and Kilgore knew it. He turned like a flash and darted up the stairs, making for the second floor. Three at a stride he covered, and succeeded in reaching the corridor above before Nick could get a line on him. Nick followed, gun in hand. On the second floor Kilgore darted into a dark chamber, and then through that to one adjoining it, where he waited till he heard Nick plunging into the one first mentioned. Then Kilgore slipped out into the hall again, hoping to retrace his steps downstairs and escape by the front door. In the way of that, however, Chick and Patsy were now in the lower hall, the former shouting lustily up the stairs: "Run him down, Nick! Run him down! We'll cover this way of escape!" An involuntary oath broke from Kilgore's lips, and at the same moment a vivid flash of lightning from the inky heavens illumined all the house. From the chamber in which he stood, Nick again caught sight of his man, and was after him in an instant. Kilgore heard him coming, and again fled through the hall and up another flight of stairs. "You'd better throw up your hands," roared Nick, as he followed. The answer came back with a yell of defiance: "Not on your life!" "You're a lost dog," cried Nick, hoping to keep him replying. "You'll not get me alive!" "Then I'll get you dead!" cried Nick, as he mounted the stairs. "You haven't got me yet!" "Next door to it, my man." This brought no answer. In a moment Nick reached the second hall, where he briefly paused to listen. Save the rain beating on the roof of the house, only one sound reached his strained ears. It was like that of some one hammering against the side of the house with some heavy object. For a moment the detective was puzzled. He could not fathom the meaning of such a sound. Then a gust of damp night air rushed through the hall and swept Nick's cheek. "Ah! an open window!" he muttered. "That's easily located." He groped his way into one of the rear chambers. There the night air was sweeping in through an open window, to the sill of which Nick quickly sprang. Now the noise he had heard was instantly explained.