“Yes. But for M. Marcel,” said Cardez, “we should not be speaking to you at this moment, M. Prevost.”

“That was a very noble act of his,” said the captain. “Ah! neither my men nor myself had thought of doing as he did. There was courage enough in us, but we should not have thought of piercing a hole in the roof. He did not lose his head; and that was the main thing.”

Just at that moment, a voice quivering with anguish, was heard, and Marcel, pale and excited, came rushing from the laboratory, exclaiming—

“Uncle Graff. Come here, quick!”

“What is the matter?” asked Cardez.

“Stay here! My uncle only!” said the young man. Monsieur Graff immediately went up to his nephew. Baudoin was already on the threshold guarding the entrance.

“Come in! Mon Dieu! Come in!” said Marcel, pushing the old man before him. “Baudoin, shut the door and place the key inside.”

“What is the matter now?” exclaimed the old man.

“Look!”

Standing there on the threshold of the capharnaum, the three men looked around in bewildered astonishment. All the signs of a desperate fight had thrown the room into the utmost disorder. A curtain, half torn from the window still open on the river, was hanging from its broken pole. Jars, retorts, and alembics of every description crushed to pieces lay scattered about the floor. On the table was a large clot of blood, still wet, as though some one had there met his death. The paper everywhere was splashed over with large red spots, and the drawer of the table lay wide open before their eyes.