There was a telegraph-apparatus on a table and a telephone on the wall; and Paul saw under a glass case a switch-board with five brass handles, which evidently corresponded by electric wires with the five mine-chambers in the tunnel.
When they passed on, Bernard and Paul continued to follow the rails along the bed of a narrow channel, hollowed out of the rock, which led them to an open space bright with many lights. A whole village lay before them, consisting of barracks inhabited by soldiers whom they saw moving to and fro. They went outside it. They then noticed the sound of a motor-car and the blinding rays of two head-lights; and, after climbing a fence and passing through a shrubbery, they saw a large villa lit up from top to bottom.
The car stopped in front of the doorstep, where some footmen were standing, as well as a guard of soldiers. Two officers and a lady wrapped in furs alighted. When the car turned, the lights revealed a large garden, contained within very high walls.
"It is just as I thought," said Paul. "This forms the counterpart of the Château d'Ornequin. At either end there are strong walls which allow work to be done unobserved by prying eyes. The terminus is in the open air here, instead of underground, as it is down there; but at least the quarries, the work-yards, the barracks, the garrison, the villa belonging to the staff, the garden, the stables, all this military organization is surrounded by walls and no doubt guarded on the outside by sentries. That explains why one is able to move about so freely inside."
At that moment, a second motor-car set down three officers and then joined the other in the coach-house.
"There's a dinner-party on," said Bernard.
They resolved to approach as near as they could, under cover of the thick clumps of shrubs planted along the carriage-drive which surrounded the house.
They waited for some time; and then, from the sound of voices and laughter that came from the ground-floor, at the back, they concluded that this must be the scene of the banquet and that the guests were sitting down to dinner. There were bursts of song, shouts of applause. Outside, nothing stirred. The garden was deserted.
"The place seems quiet," said Paul. "I shall ask you to give me a leg up and to keep hidden yourself."