At the end of quarter of an hour, they were suddenly startled by hearing a wild, piercing cry in human tones, of: "Help! Police! Murder!" The Bradys were intensely startled. It was the same voice, using the very same words they had heard the night before in West Thirty-sixth street, New York! "Good gracious! That's queer!" exclaimed Old King Brady, in tones of intense astonishment. "Did you hear it, Harry?" The boy was thinking. A startling idea flashed across his mind and he muttered: "That cry was uttered by the same person we heard in New York, and I'm convinced that it was the man called Albert Reid." "But he was murdered----" "You only suppose so. There was circumstantial evidence that he was. But after all he may yet be alive." This was a startling view to take of the matter. Old King Brady shot a quick glance at Harry and exclaimed: "You may be right. The man in the box may not have been dead after all. Perhaps he was alive, under the influence of a drug. The man who drugged us may have drugged him, too, you know. "Hark!" A chorus of fierce cries came from the hut. There was the noise of a scuffle, then a voice which sounded very much like that of a negro roared in furious tones: "Keep still, or I'll kill you!" Old King Brady rose to his feet, very much agitated. "I can't stand this much longer, Harry!" he muttered. "Come on to the hut and we'll investigate the row," replied the boy. Casting aside all caution, they rushed toward the old building. Not half the intervening distance had been covered, when suddenly the noise ceased and the light went out. The detectives halted. "Were we seen?" panted Harry. "Perhaps. Listen a moment." They remained perfectly still and the trees cast a dark shadow over the scene which the moon could not dispel. Five minutes passed. Hearing and seeing nothing unusual, Harry said: "Come on." "Wait till I light my lantern." "I'll stand guard with my pistol." Old King Brady drew out a match and lit his bull's-eye. Moving forward, they reached the hut and made a circuit of it. The door was wide open. They boldly entered the building. It contained only one room, and to the amazement of the officers, it was empty. Staring around, Old King Brady observed that there was only one door and the two windows they had been watching--one at the rear and the other at the side of the little building. The door was at another side. "Gone!" ejaculated the old detective. "Where?" asked the astonished boy. "Heaven only knows." "Search outside." Old King Brady dashed out the door. He saw by the moonlight that the little island on which the hut stood was in the midst of the swamp. If any one left it, he was bound to see them. But not a soul met his view. No one could leave the hut, cross the swamp and reach the mainland so quick that he could not see them escaping in such a short space of time. Yet he failed to see any one in the swamp. That convinced him that no one left the oasis.