Then suddenly she knew: the man below was M.Dubois, whom Olivetta, at her desire, had with unwilling but obedient frostiness sent about his business.

She had known that Jack had taken up with M.Dubois at the time the artist was doing her portrait; but she had not known that Jack was so intimate as the artist's being admitted to Jack's secret seemed to indicate.
Within herself, some formless, incomprehensible thing seemed about to happen.

During these days of solitude--and this, too, even before Matilda had gone--a queer new something had begun to stir within her, almost as though threatening an eruption.

It seemed a force, or spirit, rising darkly from hitherto unknown spaces of her being.

It frightened her, with its amorphous, menacing strangeness.