That Affair Next Door by Anna Katharine Green

I felt that I had made an advance. It was a small one, no doubt, but it was an advance. It would not do to rest there, however, or to draw definite conclusions from what I had seen without further facts to guide me. Mrs. Boppert could supply these facts, or so I believed. Accordingly I decided to visit Mrs. Boppert.

Not knowing whether Mr. Gryce had thought it best to put a watch over my movements, but taking it for granted that it would be like him to do so, I made a couple of formal calls on the avenue before I started eastward. I had learned Mrs. Boppert's address before leaving home, but I did not ride directly to the tenement where she lived. I chose, instead, to get out at a little fancy store I saw in the neighborhood.