In a few minutes, that is to say, two hundred yards farther on, the light of their pocket-lantern showed them the steps of a staircase on their right.
"First turning," remarked Paul. "I take it there must be at least three of them."
"Where does the staircase lead to?"
"To the château, obviously. And, if you want to know to what part, I say, to the room with the portrait. There's no doubt that this is the way by which Major Hermann entered the château on the evening of the day when we attacked it. He had his accomplice Karl with him. Seeing our names written on the wall, they stabbed the two men sleeping in the room, Private Gériflour and his comrade."
Bernard d'Andeville stopped short:
"Look here, Paul, you've been bewildering me all day. You're acting with the most extraordinary insight, going straight to the right place at which to dig, describing all that happened as if you had been there, knowing everything and foreseeing everything. I never suspected you of that particular gift. Have you been studying Sherlock Holmes?"
"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?"