Then, with a lightninglike move, Nick’s hand shot across the table and seized the beard of the startled man. Conroy shrank back with a terrible veil. His beard, his glasses, a neatly fitted wig--all were torn off by the detective’s irresistible hand, revealing the ghastly, horrified, rage-distorted face of--David Mack. “Aha! I thought so,” Nick shouted, leaping to his feet and reaching for his revolver. “You are the chief abductor, Mack, after all.” Nick did not, however, succeed in drawing his weapon nor in making the arrests he had in view. The entire sensational episode transpired in the quarter part of a second. The yell scarce had left David Mack’s lips, when, through a doorway back of the detective, two men leaped with uplifted bludgeons and fell upon Nick from behind, just as he was springing to his feet. One of them was a brawny, powerful man with red hair--Andy Duffy himself. The other was Gleason, his chauffeur, mentioned in Patsy’s hearing by Kate Crandall. All three men were with the woman in the house when Nick rang the bell, and their immediate suspicions had led to what followed. Nick heard their steps behind him even while he was speaking, and he sprang to one side to avoid a blow--but the move was an instant tardy. A blackjack in Duffy’s hand fell squarely on the side of Nick’s head. The terrific blow staggered him. Another from Gleason followed it. The third came from his more brawny assailant. All fell in the hundredth part of a second. Nick felt his knees buckle under him. The room went whirling around like a top. The beginning and end were more quick than one could imagine. Vengeful shouts from David Mack, exultant cries from Kate Crandall, the hoarse oaths and imprecations of his merciless assailants--all suddenly sounded faint and far away, and the light through the lace-draped windows turned to inky darkness. CHAPTER VIII. UNDER THE SURFACE. It was not a sudden inspirational suspicion, no inexplicable intuitive conviction, that had caused Nick Carter to snatch a disguise from the face of Jack Conroy, so called, and unmask the treacherous scoundrel chiefly responsible for the abduction of Amy Madden. Nick Carter had dug out this possibility from under the superficial facts and circumstances before leaving his business office that afternoon. He had asked himself numerous pertinent questions leading up to it. Why had Kate Crandall, surely one of the abductors, lately left her position with Madden, Mellen & Mack? What reason could she have had for giving up a remunerative situation? Why did it really happen that, instead of dealing directly with the father of the stolen child, the abductors had selected to negotiate with his junior partner, David Mack? What was the true reason for that? Were there secret relations existing between these two, Kate Crandall and David Mack?