Gasping, Atherton tied his scarf over his mouth, and dashed as hard as he could through the inky darkness, keeping his left hand on the wall to guide him. Stumbling over the silver bowl at the foot of the stairs was the first intimation he received of the fact that he had reached the end of the passage. Then, as he mounted the spiral stairs, to his utter relief he heard Mr Buckley's voice calling him by name. Removing his scarf, Atherton gave a reassuring answer. "Thank heaven, you're safe!" replied the Scoutmaster, as Atherton emerged through an irregularly shaped hole that took the place of the narrow opening into the butler's room. "And Mayne and Green?" "They're all right, only a bit shaken up." In the room, in addition to Mr Buckley, were Sir Silas Gwinnear, Polglaze the detective, and a gentleman whom Atherton had not seen before, and who was a mining engineer for one of the neighbouring "wheals" or mines, and three workmen. "We knew something was amiss," explained the Scoutmaster. "Soon after you descended the tunnel for the second time it came on to pour with rain. Phillips suggested to me the danger of one portion of the passage being filled with water, and he and I going down found this to be the case, and that your retreat was cut off, unless you succeeded in turning the revolving stone. "Thinking that there was a chance of your not being able to do so, Phillips and I made our way across the mainland, and on to Polkerwyck House. "We found the secret opening still remained fast closed. We hammered at it, tried crowbars, and did everything to attract your attention. Green tells me you never heard a sound." "We made as much row as we could, sir," said Atherton. "The walls must be practically soundproof." "I should say they are not soundproof now," continued Mr Buckley. "On Sir Silas's advice we sent to Polkarnis Mine for some men accustomed to the use of explosives, and this gentleman--Mr Copperas, the electrical works' manager--kindly came over to give his technical assistance." "Yes, it's a wonder we didn't do more harm," added Mr Copperas. "Since we heard no sounds from within we naturally concluded that the three of you were farther along the tunnel. However, all's well that ends well, and your two chums have been through an experience I never wish to meet with: standing within a few feet of five pounds of gun-cotton when it exploded." "Now, Atherton, we must be making a move," declared the Scoutmaster. "It will soon be dark, and you've had a couple of very trying days." "How about the silver bowl, sir?" said the Scout, who had already noticed the signs of preparations of bricking up the gap. "I'll get it if you like." "Don't worry about that, Atherton," interposed Sir Silas. "Get a good night's rest. You can have a bed here if you wish." "No, thank you, sir," replied Atherton. "I think I shall sleep pretty soundly in camp."