Out of the wooden case Professor Tufts had taken an ingenious little apparatus, of which the essential feature was an oxyhydrogen blowpipe. With the assistance of his companions he was directing the flame to that part of the safe door which surrounded the lock. So intense was the heat of the flame, that it melted the steel as easily as a hot knife cuts through butter. In an incredibly short time a circular hole had been cut through the door. A minute or two later the safe was open, and Kinsley and Frost were about to pack the cases of jewelry into the leather box. Suddenly the waiter saw something which almost caused his heart to stop beating. CHAPTER VII. A SHOT FROM THE DARK. The study door was opposite the window. It was shut, but not locked, of course, and all at once Max saw a knob begin to turn. Apparently it made no sound, for the four men went on with their work--the lawyer and Frost opening the bag preparatory to putting the jewel cases into it, and Atherton and Professor Tufts stowing away the apparatus in its case. Every fiber of the waiter’s being tingled with suppressed excitement. It was only too plain that somebody was outside the door, preparing to burst in and take the burglars by surprise. What ought he to do? Should he call out and warn them of their danger? Should he make his own escape before the storm burst? He had no time to decide, for all at once, with dramatic suddenness, the door was flung open, and Francis Massey sprang into the room clad in dressing gown and slippers, and armed with a revolver. “Hands up, if you don’t want a bullet in you!” he cried, leveling his weapon at Atherton with one hand, while with the other he pressed the switch beside the door and flooded the room with light. The intruders had been content with their electric torches and the brilliant flame of the blowpipe. With simultaneous cries of dismay the four men spun around and faced the owner of the house. “Stop that instantly, or I’ll fire!” cried the latter, as Atherton’s hand stole toward his pocket. “Put your hands up, all of you! This revolver is loaded in every chamber, and as you may be aware, I have some little reputation as a crack shot.” This was true enough, for Francis Massey had been a famous sportsman in his younger days, and was still an expert with the revolver. Half the length of the room separated him from the four men, and if they had attempted to rush him, he could have--and probably would have--dropped all four of them before they could have reached him. “That’s better!” he said grimly, as the quartet quickly raised their hands above their heads. “Now, kindly oblige me by walking backward and standing with your backs to that wall behind you. Be quick about it!” The waiter outside could have laughed at the ignominious spectacle presented by the four masked burglars as they silently and sullenly shuffled backward, and ranged themselves in a line against the wall.