"Is what you said true, then? Is he in the cellars of the Villa des Glycines?"
"I have every reason to think so."
"But how do you know? . . . What clue? . . ."
"That's my secret. I can tell you one thing: the revelation will be—what shall I say—sensational. Have you finished?"
"Yes."
"My car is behind the Madeleine. Join me there."
At Garches, Sernine sent the motor away, and they walked to the path that led to Geneviève's school. There he stopped:
"Listen to me, lads. This is of the highest importance. You will ring at the House of Retreat. As inspectors, you have your right of entry, have you not? You will then go to the Pavillon Hortense, the empty one. There you will run down to the basement and you will find an old shutter, which you have only to lift to see the opening of a tunnel which I discovered lately and which forms a direct communication with the Villa des Glycines. It was by means of this that Gertrude and Baron Altenheim used to meet. And it was this way that M. Lenormand passed, only to end by falling into the hands of his enemies."
"You think so, governor?"
"Yes, I think so. And now the point is this: you must go and make sure that the tunnel is exactly in the condition in which I left it last night; that the two doors which bar it are open; and that there is still, in a hole near the second door, a parcel wrapped in a piece of black cloth which I put there myself."