My only possible way to the second floor lay by the back of the house.

I had looked up at it two or three times, while walking in the garden after dinner with Alicia.

What had I brought away in my memory as the result of that casual inspection of my host's back premises?
Several fragments of useful information.
In the first place, one of the most magnificent vines I had ever seen grew against the back wall of the house, trained carefully on a strong trellis-work.

In the second place, the middle first-floor back window looked out on a little stone balcony, built on the top of the porch over the garden door.

In the third place, the back windows of the second floor had been open, on each occasion when I had seen them--most probably to air the house, which could not be ventilated from the front during the hot summer weather, in consequence of the shut-up condition of all the windows thereabouts.