"Boys," he said, "according to custom, being Chief of Police of Mona, I am to make the arrest. That I will do, but let me tell you right here it is Mr. Oakes who will point out the culprit. I have been unable to get a clue, and I am damned if I'll take credit from a man like that." As he spoke he thumped the table with his hamlike fist. Hallen was not a clever man. He was about the average, perhaps a little above; but he was as honest as the day was long--a staunch, vigorous man--and we all admired him. "Sit down," commanded Oakes harshly. "Don't give us any more such nonsense," and the Chief sat down, while we all half smiled at the discomfiture of both. "Now, gentlemen," said Oakes, "let us keep our wits about us. First let me identify O'Brien, if possible, and let us study Maloney afterward. Remember, if O'Brien is not Larkin the detective, my case is _not_ ready; if he _is_ the man we suspect, then we must turn to Maloney regardless of any presence of insanity now, as he maybe in the quiescent period, so called, and may succeed in baffling us. Having once excluded O'Brien from suspicion, we will be justified in action against Maloney. We must prove his knowledge of the heavy revolver, if possible. Then if we succeed in forging that link to our chain, we will move quickly; upon his arm should be the cross seen by the dying Mr. Mark." _CHAPTER XXIII_ _The Test_ As Oakes ceased speaking there came a silence. Although we were many there, there was not a motion for a space of seconds--not a sound save the deep breathing of Hallen and of some of the others upon whom the duty of the hour was to fall. Men trained for such scenes--always alive to the possibilities, always alert for trickery or treachery--are yet but human, and subject to the tension that is felt even by the most courageous. Then, in obedience to a signal from Oakes, Martin appeared, escorting O'Brien, who was limping, into the room, and to the chair facing Oakes. It soon became evident to us that Oakes's real identity was unknown to O'Brien. Even if the latter were the detective Larkin, he had failed to realize that Mr. Clark was anything but the agent for the property. "You are wounded, my man! They tell me it happened in the Highway the other day, and that afterwards, at night, you chased Maloney on the plains of Mona, after he had fired upon us. Tell us about it, O'Brien." Oakes's voice was calm and strong, but in it I fancied I detected a note of pity. O'Brien hesitated, stammered. "How did you know when I was shot?" he exclaimed. "I told no one." Oakes smiled slightly. "Out with your story, O'Brien. Did you chase Maloney for revenge, or for revenge and business?" O'Brien straightened in the chair. "Who is this man Clark? How peculiar these questions are!" his look plainly said. "Why, for revenge, of course," he answered. "Let's see your wound," commanded Oakes.