"It gave our presence here away, and will put them on their guard." "Can't be helped. We know Mason is really here, however. He's desperate now, and won't hesitate to murder us if he can, to avoid arrest." "Who was the other masked man, I wonder?" "Must be the party who helped him to get the box off the train, and carry the body of Mr. Dalton to the house in the swamp." "Oh, Mason hadn't a hand in stealing the box from the baggage car. He got off before the cars reached this point of the swamp, I'm sure." "Then that fellow must have had other helpers, as he could not very well have done the job unaided," said Harry. "Let us get around to the board walk, and try to reach the hut. If they are heading for that building, we can meet them there." "Here's a quicker way," said the boy, pointing at a boat. It was a crude affair, half hidden in the reeds. They embarked, and rowed out through the lagoons. The water was mostly quite shallow, but there were places where the detectives could not see bottom. In a short time they reached the island in the swamp, and, leaping ashore, they ran over to the hut. One glance inside was enough for them. "The place is deserted," was Harry's comment. "Wait for them. We may have headed off the rascals." "If they saw us coming here, they will shun the place." "There was no way to conceal our movements." An hour went by quietly enough. Not a soul ventured near the place, and Harry grew restless. He made a circuit of the island, scanning every section of the swamp, and finally returned to his partner, and said: "We've had our labor for our pains." "No sign of them, eh?" "No. Could they have gone to the Dalton residence?" "More than likely. As Mason is skulking about this neighborhood, he, of course, must be living in the big house." "Come on over there then." "Get in the boat. It will save us making a detour of the swamp." They saw numerous channels by following which they could reach the mainland quite close to the big house. Gliding slowly over the water, the boat finally touched the shore, and the two detectives debarked and pulled the punt up on the bank. There were rocks, trees and bushes all around. As they stood looking for a path, a voice reached their ears, saying: "Sim, where are you?" Then the negro answered: "Near de sho', Massa Ronald." Old King Brady held up his finger warningly. "There they are!" he whispered. Just then Mason's voice was heard again: "Keep on shouting, Sim, so I can locate you." "Dis way! Dis way!" cried the darky. The detectives glided in the direction of the voice, and, passing through the shrubbery, they parted the bushes, and entered a clearing. A little brook was gushing from the midst of the verdure, and emptied its waters into a shallow pool, the bottom of which was composed of pure white sand. Pausing on the brink of this pool, the detectives glanced searchingly around, and heard the negro laughing amid the shrubbery.