"Not even Arsène Lupin," said Paul, moving on again. "But I've been ill and I have thought things over. Certain passages in Élisabeth's diary, in which she spoke of her perplexing discoveries, gave me the first hint. I began by asking myself why the Germans had taken such pains to create a desert all around the château. And in this way, putting two and two together, drawing inference after inference, examining the past and the present, remembering my meeting with the German Emperor and a number of things which are all linked together, I ended by coming to the conclusion that there was bound to be a secret communication between the German and the French sides of the frontier, terminating at the exact place from which it was possible to fire on Corvigny. It seemed to me that, _a priori_, this place must be the terrace; and I became quite sure of it when, just now, I saw on the terrace a dead tree, overgrown with ivy, near which Élisabeth thought that she heard sounds coming from underground. From that moment, I had nothing to do but get to work." "And your object is . . . ?" asked Bernard. "I have only one object: to deliver Élisabeth." "Your plan?" "I haven't one. Everything will depend on circumstances; but I am convinced that I am on the right track." In fact all his surmises were proving to be correct. In ten minutes they reached a space where another tunnel, also supplied with rails, branched off to the right. "Second turning," said Paul. "Corvigny Road. It was down here that the Germans marched to the town and took our troops by surprise before they even had time to assemble; it was down here that the peasant-woman went who accosted you in the evening. The outlet must be at some distance from the town, perhaps in a farm belonging to the supposed peasant-woman." "And the third turning?" said Bernard. "Here it is." "Another staircase?" "Yes; and I have no doubt that it leads to the chapel. We may safely presume that, on the day when my father was murdered, the Emperor had come to examine the works which he had ordered and which were being executed under the supervision of the woman who accompanied him. The chapel, which at that time was not inside the walls of the park, is evidently one of the exits from the secret network of roads of which we are following the main thoroughfare." Paul saw two more of these ramifications, which, judging from their position and direction, must issue near the frontier, thus completing a marvelous system of espionage and invasion. "It's wonderful," said Bernard. "It's admirable. If this isn't Kultur, I should like to know what is. One can see that these people have the true sense of war. The idea of digging for twenty years at a tunnel intended for the possible bombardment of a tiny fortress would never have occurred to a Frenchman. It needs a degree of civilization to which we can't lay claim. Did you ever know such beggars!"