Where does Margeurite see love from her husband after the ball?

Marguerite sees love in her husband's eyes and bearing.... a brief glimpse of the man who still loves her.

The dim, grey light of early dawn seemed to make his tall form look taller and more rigid. The lazy, good-natured face looked strangely altered. Marguerite, excited, as she was, could see that the eyes were no longer languid, the mouth no longer good-humoured and inane. A curious look of intense passion seemed to glow from beneath his drooping lids, the mouth was tightly closed, the lips compressed, as if the will alone held that surging passion in check.

Marguerite Blakeney was, above all, a woman, with all a woman's fascinating foibles, all a woman's most lovable sins. She knew in a moment that for the past few months she had been mistaken: that this man who stood here before her, cold as a statue, when her musical voice struck upon his ear, loved her, as he had loved her a year ago: that his passion might have been dormant, but that it was there, as strong, as intense, as overwhelming, as when first her lips met his in one long, maddening kiss.