"To explain that, monsieur, is one of the reasons I have brought you here." And moving towards the window she opened it cautiously. As she did so there appeared, about three feet or more away, the grey and mottled surface of a blank wall.
"Look!" she said.
I looked out of the window. The walls of the two houses stood about three feet apart. Below me was a deep, narrow space, shut in on all sides except from the top. In the opposite wall was a window partly open, below which ran a narrow ledge. This window faced the one I was standing at, but was placed about a yard or so higher, so that anyone standing there could look into the room in which we were. All this I took in, and then turned to La Marmotte.
"Monsieur," she said, "that house is where Antoine de Mouchy lives, and where, within an hour's time, he is to meet the Vidame and some others to discuss their plan. If you would learn it you must learn it from there." And she pointed to the window above me.
I was about to speak, but she stopped me.
"Listen! I know that house from garret to cellar, for I lived there once. That window leads to an empty room. A door to the right leads into De Mouchy's study, which looks over the Rue de la Harpe, and standing at that door you can hear every word that passes within. Will you risk it?"
"The getting there is possible, but it is the retreat that I am doubtful of."
"I have provided for that." And opening a box that lay near her she pulled out a short coil of stout rope with an iron hook fixed at each end.
"Fasten one hook to the window there, and throw me the rope. I will fasten the other here, and you will have a passage back. I will wait here for you."
I glanced out of the window again. On the left was the Passage of Pity with its dreary, deserted houses, on the right, above me, was a glimpse of sky. Now and again we heard the cooing of pigeons and the flutter of their wings amongst the eaves, but except for this there was no sound, and we were perfectly unobserved.