It could be simply enough expressed; she had had the glimmer of it the day before in her idea that he needed no more help than she had already given; that it was help he himself was prepared to render.

He had come up to town but for three or four days; he had been absolutely obliged to be absent after the other time; yet he would, now that he was face to face with her, stay on as much longer as she liked.
Little by little it was thus clarified, though from the first flash of his re-appearance she had read into it the real essence.
That was what the night before, at eight o'clock, her hour to go, had made her hang back and dawdle.

She did last things or pretended to do them; to be in the cage had suddenly become her safety, and she was literally afraid of the alternate self who might be waiting outside.

_He_ might be waiting; it was he who was her alternate self, and of him she was afraid.

The most extraordinary change had taken place in her from the moment of her catching the impression he seemed to have returned on purpose to give her.