Finally he asked in sharp, metallic tones: "Well, which shall it be--obey me, and sign a check, or remain chained here like a wild beast, and perish of starvation?" For a moment there was a deep silence. Slowly the prisoner removed his trembling hands from his wan, pinched face, and said in reproachful tones: "I can't stand this any longer." "Then you will sign the check?" eagerly asked Mason. "Yes. And you will then give me my liberty?" "The moment you affix your signature to this check, we will give you food. And the moment I get the money, you will get your liberty." "Give me the check." Mason drew the pen and paper from his pocket, eagerly strode over to the poor wretch, and held them out to him. But instead of taking the pen, Dalton gave one mighty leap, clutched the wretch by the throat with both hands, and, choking the villain till he grew black in the face, he yelled frantically: "I've got you at last, you dog; and by the eternal, I'll kill you, if it's the last thing I do on earth! Die, confound you, die! And this is the vengeance I've been craving all through the moments of torture you've put me to in the past!" He hurled Mason upon the floor, pinioned him to the ground, with a knee on his chest, and Sim, with an oath, rushed to his master's aid. CHAPTER XVI. ESCAPING FROM THE CAVES. The Bradys were very much astonished by the violent turn affairs had taken. In the prisoner's desperate attack they saw the last expiring act of a wronged man thirsting to avenge his injuries. It pleased them to see Mason caught in a trap. But when the negro showed signs of attacking Mr. Dalton, they realized that it was about time for them to act. Harry had a revolver in his hand. Aiming at Sim, he fired. The sudden report startled every one. A yell of agony escaped the negro, and he paused and staggered back with a wound in his side which filled him with pain. The shot caused Dalton to relax his awful grip. Hoarsely gasping for air to breathe, Mason sprang to his feet. "I'm shot!" groaned the coon. "It's the detectives!" gasped Mason, seeing the Bradys. "We'll get hung!" screamed Sim, in tones of horror. "Run for the swamp passage!" "Put out de light!" Mason seized the lantern and hurled it to the ground. There was a crash, a jingle of broken glass, then dense gloom. The Bradys paused. They heard the patter of rushing footsteps crossing the floor, and made violent efforts to get out and unmask their lanterns. Only a few moments passed before they had a light flashing on the scene, and they swept it around the cavern. But they saw nothing of the two villains. They had made good their escape. Mr. Dalton stood by the rock, trembling and anxious, and after a few moments of silence, he asked, eagerly: "Who is that?" "Friends," cheerily replied Harry. "Thank Heaven for that!" "Harry, the villains are gone." "Can you see how they got out?" "Yes. There's another tunnel."