"We go daily to the village of Passy adjoining my home, where you take the waters in a beautiful garden. Streams and waterfalls pour down on all sides, this way and that, in artfully leveled beds. I am known to like skilful mechanism, so I have been shown the basin where the waters of all the rivulets meet and mingle. There stands a little marble figure in the midst; and the weight of water is strong enough to turn it a quarter circle to the left and then pour down straight to the Seine by a conduit, which opens in the ground of the basin." Patrice closed the book; and Don Luis went on to explain: "Things have changed since, no doubt, thanks to the energies of Essarès Bey. The water escapes some other way now; and the aqueduct was used to drain off the gold. Besides, the bed of the river has narrowed. Quays have been built, with a system of canals underneath them. You see, captain, all this was easy enough to discover, once I had the book to tell me. _Doctus cum libro._" "Yes, but, even so, you had to read the book." "A pure accident. I unearthed it in Siméon's room and put it in my pocket, because I was curious to know why he was reading it." "Why, that's just how he must have discovered Essarès Bey's secret!" cried Patrice. "He didn't know the secret. He found the book among his employer's papers and got up his facts that way. What do you think? Don't you agree? You seem not to share my opinion. Have you some other view?" Don Luis did not reply. He stood looking at the river. Beside the wharves, at a slight distance from the yard, a barge lay moored, with apparently no one on her. But a slender thread of smoke now began to rise from a pipe that stood out above the deck. "Let's go and have a look at her," he said. The barge was lettered: LA NONCHALANTE. BEAUNE They had to cross the space between the barge and the wharf and to step over a number of ropes and empty barrels covering the flat portions of the deck. A companion-way brought them to a sort of cabin, which did duty as a stateroom and a kitchen in one. Here they found a powerful-looking man, with broad shoulders, curly black hair and a clean-shaven face. His only clothes were a blouse and a pair of dirty, patched canvas trousers. Don Luis offered him a twenty-franc note. The man took it eagerly. "Just tell me something, mate. Have you seen a barge lately, lying at Berthou's Wharf?" "Yes, a motor-barge. She left two days ago." "What was her name?" "The _Belle Hélène_. The people on board, two men and a woman, were foreigners talking I don't know what lingo. . . . We didn't speak to one another." "But Berthou's Wharf has stopped work, hasn't it?" "Yes, the owner's joined the army . . . and the foremen as well. We've all got to, haven't we? I'm expecting to be called up myself . . . though I've got a weak heart." "But, if the yard's stopped work, what was the boat doing here?"