I heard them rush frantically towards it, trying to open it, but their efforts were unavailing. Loud imprecations escaped them, for they believed that some person had imprisoned them. If they succeeded in escaping they would certainly discover me, therefore my position was one of extreme peril. But I recollected the strange ticking of that clock which had commenced when the secret cupboard had been opened. The ticking had now ceased, therefore the door had closed automatically upon the intruders. By some clever contrivance Nardini had connected his secret hiding-place with the door that had been strengthened and lined with steel, enamelled white to match the wood-work of the salon. By a clockwork arrangement the door would evidently close upon the inquisitive person who opened the cupboard at a certain time afterwards. When the little clock standing upon the pearl-inlaid cabinet had suddenly broken the silence by ticking it had attracted my attention, but I quickly forgot it in watching the trio so narrowly. The study window was evidently strongly barred, as were all the windows of the ground floor of the villa, the bars being built into the wall outside the house in such a manner that they could only be filed through, an operation which would take considerable time even with proper tools. They hammered upon the door and threw their weight upon it, but it did not budge. Evidently by the same mechanical contrivance several strong steel bolts had been shot into their sockets. The trio at the very moment of their sudden acquisition of Nardini's dishonestly obtained wealth had been entrapped. "We're discovered!" I heard Miller cry in English. "Whoever has found us has locked us in!" It never occurred to them that the cupboard and the door were connected, or that Nardini had invented such an ingenious contrivance in order to entrap any thief who might discover his secret. "We must get out of this as quickly as possible!" Gavazzi exclaimed breathlessly. "Let's make the division of the money afterwards." "The window!" suggested the younger man, but a rapid examination proved it to be too strongly barred. I heard them within the room consulting with each other as to what could be done, and was amused at their chagrin, having discovered the dead man's hoard only to be so unexpectedly imprisoned with the wealth upon them. The two Italians showered fierce imprecations upon whoever had bolted them in, and vowed that the police should never take them alive. They knew, too well, the serious charge they would have to face, for they knew that the body of the detective left in charge would be discovered behind the side door. A heavy piece of furniture was brought to play upon the study door, but the sound made as they battered with it revealed to them that they were endeavouring to break down iron.