The drawing-room at Gardencourt was an apartment of great distances, and, as the piano was placed at the end of it furthest removed from the door at which she entered, her arrival was not noticed by the person seated before the instrument.
This person was neither Ralph nor his mother; it was a lady whom Isabel immediately saw to be a stranger to herself, though her back was presented to the door.

This back--an ample and well-dressed one--Isabel viewed for some moments with surprise.

The lady was of course a visitor who had arrived during her absence and who had not been mentioned by either of the servants--one of them her aunt's maid--of whom she had had speech since her return.

Isabel had already learned, however, with what treasures of reserve the function of receiving orders may be accompanied, and she was particularly conscious of having been treated with dryness by her aunt's maid, through whose hands she had slipped perhaps a little too mistrustfully and with an effect of plumage but the more lustrous.

The advent of a guest was in itself far from disconcerting; she had not yet divested herself of a young faith that each new acquaintance would exert some momentous influence on her life.
By the time she had made these reflexions she became aware that the lady at the piano played remarkably well.