Read it through once

The next day was a Sunday, and if she were "going out" on a Sunday evening it could, of course, be only to Mrs. Lemuel Struthers's. He felt a slight movement of annoyance, not so much at her going there (for he rather liked her going where she pleased in spite of the van der Luydens), but because it was the kind of house at which she was sure to meet Beaufort, where she must have known beforehand that she would meet him--and where she was probably going for that purpose.