"He's over there!" said Harry, pointing across the pool. "Watch a moment, and we may locate him," Old King Brady whispered. Standing stock still, they listened intently. In fact, they were so absorbed in looking for the negro that they did not see two men crouching in the bushes close behind them. They were the two masked fellows who first assailed them. As stealthily as tigers, they crept from their covert. When but a few feet separated them from the Bradys, they made a combined rush, with their hands outstretched. The alert detectives heard them coming, and glanced around. Before they could defend themselves, however, the on-comers struck them heavily, and knocked the detectives into the pool. Too late the Bradys realized that the negro had been decoying them purposely to that dangerous place. For, the moment they fell into the pool, they sank in the sand. Trying to scramble to their feet, the Bradys found their legs going down in the treacherous sand rapidly. Then the truth flashed across their minds, and Harry cried: "By Heavens, they've thrown us into a bed of quick-sand!" "Try to reach the shore--quick!" panted Old King Brady. They made the most desperate efforts, but only floundered around helplessly, and each moment got caught more firmly in the deadly sand. CHAPTER XII. AN UNEXPECTED FRIEND. The moment Ronald Mason and his companion hurled Old and Young King Brady in the bed of quick-sand, they ran away. Dodging behind the rocks, they hid themselves. By this time the sun was rising. Finding it impossible to extricate themselves from the deadly grip of the treacherous sand, the detectives ceased their struggles. "It's useless, Harry," said the old sleuth, despairingly. "If we remain passive, we'll soon sink beyond our depth, and perish." "Yell at the top of your voice. Some one may hear us." "Help! Help! Help!" shouted Harry. They were shouting this way when Mason came from behind the rocks, pulled off his mask, and grinned sardonically at them. Finally he said in sarcastic tones: "Well, how do you like dying by inches?" "This was cowardly of you, Mason," said Old King Brady, bitterly. "It's my way of gaining revenge." "Why don't you give us a fair show to fight for our lives?" "Because you are so dangerous you might beat me." "Help us out of here, and act like a man." "I won't. See all the harm you've done me. In the first place, you've cheated me out of a fortune. In the second place, you prevented me from getting the girl I loved. In short, you've baffled me at every turn, after I made the most elaborate preparations to succeed." "We did our duty." "Oh, that be hanged! You'd kill me to do your duty, and I'm justified in ridding myself of such enemies as you two are." "If you hadn't done wrong you would not have had us after you." "Well, I know that very well. It's stale news. But I had an object in what I did, and you interfered and foiled me. I didn't do any one much harm, and----"