As it was, a terrible weakness oppressed him. His fall into the basement had jarred him terribly, and it was with difficulty that he could stand alone. The walls seemed to whirl about in a mad waltz, and the faces of the three villains seemed one mass of grinning demons. "Halt!" Nell Darrel, white as death, yet with the fires of a resolute purpose blazing in her eyes, thrust forward her pistol. "It's pretty Nell on a lark!" exclaimed Professor Ruggles. "It will be better for you not to make any resistance, for the moment you attempt it, that moment death will come to both of you. Be wise in time." The Professor advanced a step. "Stop there," sternly ordered the girl. "Aye! stop there," repeated Dyke, in a voice husky from very weakness. "We will not be taken alive. Do you know on what dangerous grounds you are treading? This block is surrounded by members of the force, and any harm offered to Nell or myself speedily avenged." A jeering laugh answered the detective. "It is wrong to tell such a whopper, Mr. Darrel, especially when one is on the verge of eternity," said Ruggles, showing his teeth. The situation was interesting. "Will you permit us to depart from here?" questioned the detective, suddenly. This speech brought a laugh to the lips of Darlington Ruggles. "You do not seem to know me!" he said. "I know that you pretend to be a professor of some sort, but I believe that you are in disguise. I think, if you would cast aside that red hirsute covering, we should see----" "Zounds! Go for him, boys," cried Professor Ruggles in a loud voice, completely drowning the faint accents of Dyke Darrel. The two men who kept the Professor company, made a quick move to seize the twain in front of them. On the instant came a flash and sharp report. One of the villains staggered and sank with a groan against the stairs. "I--I'm shot!" he gasped. "The she jade!" It was Nick Brower who uttered the hissing cry of rage, and the next instant the villain's revolver flashed. "My God! You have killed Nell!" It was a cry expressive of the deepest agony, as the weak and reeling detective caught the form of his sister in his arms, as she fell backward, with the blood streaming down her face. Poor Nell! She hung a dead weight in the arms of Dyke Darrel--murdered by the hand of a brutal assassin. No wonder the bruised and almost helpless man-hunter groaned with inward anguish at the sight. He fell no easy prey into the hands of his enemies, however. Staggering backward, and easing his bleeding relative to the ground, he turned with a mad cry and dashed at the throat of Professor Darlington Ruggles. Both men staggered across the floor against the stairs. "I will strangle you for this," hissed the enraged detective. "Help!" gasped Ruggles.