At the end of the hall was a large room crowded with officers. Beyond this was a smaller room where six men, each with his secretary, sat around a long table. At its head sat a plump little man, with white hair and bristling white mustache, which contrasted strongly with a face darkened and reddened by exposure to wind and rain, and lighted by a pair of eyes incredibly bright. He was busy with a memorandum, but looked up as Stewart and his companion entered. "Well, Fernande?" he said; but Stewart did not know till afterward that the man at his side was the famous head of the French Intelligence Department, the eyes and ears of the French army--captain of an army of his own, every member of which went daily in peril of a dreadful death. "General," said Fernande, in a voice whose trembling earnestness caused every man present suddenly to raise his head, "I have the pleasure of introducing to you an American, Mr. Bradford Stewart, who, at great peril to himself, has brought you a message which I believe to be of the first importance." General Joffre bowed. "I am pleased to meet Mr. Stewart," he said. "What is this message?" "It is in these letters, sir," said Stewart, and placed the envelopes in his hand. The general glanced at them, then slowly drew out the enclosures. "We shall need a candle," said Fernande; "also a flat dish of water." One of the secretaries hastened away to get them. He was back in a moment, and Fernande, having lighted the candle, took from his waistcoat pocket a tiny phial of blue liquid, and dropped three drops into the dish. "Now we are ready, gentlemen," he said. "You are about to witness a most interesting experiment." He picked up one of the sheets, dipped it into the water, then held it close to the flame of the candle. Stewart, watching curiously, saw a multitude of red lines leap out upon the sheet--lines which zigzagged this way and that, apparently without meaning. But to the others in the room they seemed anything but meaningless. As sheet followed sheet, the whole staff crowded around the head of the table, snatching them up, holding them to the light, bending close to decipher minute writing. Their eyes were shining with excitement, their hands were trembling; they spoke in broken words, in bits of sentences. "The enceinte----" "Oh, a new bastion here at the left----" "I thought so----" "Three emplacements----" "But this wall is simply a mask--it would present no difficulties----" "This position could be flanked----" It was the general himself who spoke the final word. "This is the weak spot," he pointed out, his finger upon the last sheet of all. Then he turned to Stewart, his eyes gleaming. "Monsieur," he said, "I will not conceal from you that these papers are, as Fernande guessed, of the very first importance. Will you tell us how they came into your possession?"