Gurdon did not appear to be listening. He strode resolutely down the stairs into the hall and stood for some moments contemplating the panels before him. The panels were painted white; they were elaborately ornamented with wreaths of flowers after the Adams' style of decoration. Then it seemed to Gurdon that two pairs of panels, one above and one below, had at one time taken the formation of a doorway. He tapped on one of the panels, and the drumming of his fingers gave out a hollow sound. Gurdon tapped again on the next panel, but hardly any sound came in response. He looked triumphantly at Venner. "I think we have got it at last," he said. "Do you happen to have a knife in your pocket? Unless I am greatly mistaken, the decorations around these panels come off like a bead. If you have a knife with you we can soon find out." Venner produced a small knife from his pocket, and Gurdon attempted to insinuate the point of the blade under the elaborate moulding. Surely enough, the moulding yielded, and presently came away in Gurdon's hands. "There you are," he said. "It is exactly as I told you. I thought at first that those mouldings were plaster, but you can see for yourself now that they are elaborately carved wood." Venner laid the ornament aside and stood watching Gurdon with breathless interest while the latter attacked another of the mouldings. They came away quite easily, pointing to the fact that they must have been removed before within a very short period. Once they were all cleared away, Gurdon placed the point of the knife behind one of the panels, and it came away in his hands, disclosing beyond a square hole quite large enough for anybody to enter. Here was the whole secret exposed. "Exactly what I thought," Gurdon said. "If I removed all the mouldings from the other three panels there would be space enough here to drive a trap through. I think we have been exceedingly lucky to get to the bottom of this. How clever and ingeniously the whole thing has been managed! However, I don't think there is any occasion for us to worry about moving any more of the panels, seeing that we can get through now quite easily. Wouldn't it be just as well to put all the lights out?" "I haven't thought of that," Venner muttered. "On the whole, it would be exceedingly injudicious not to extinguish all the lights. We had better go on at once, I think, and get it over." The house was reduced to darkness, and very quietly and cautiously the two adventurers crept through the panel. They were in the hall on the other side, of which fact there was no doubt, for they stepped at once off a marble floor on to a thick rug which deadened the sound of their footsteps. They had, naturally enough, expected to find the whole place in darkness, and the tenant of the house and his servants in bed. This, on the whole, would be in their favor, for it would enable them to take all the observations they required with a minimum chance of being disturbed.