Will you ?' 'Of course.

Thank you.' He had hardly spoken the words when a servant opened the door and Lady Maud came in.

She had not dropped the opera cloak she wore over her black velvet gown; she was rather pale, and the look in her eyes told that something was wrong, but her serenity did not seem otherwise affected.

She kissed Margaret and gave her hand to Logotheti.
'We dined early to go to the play,' she said, 'and as there's a curtain-raiser, I thought I might as well take a hansom and join them later.' She seated herself beside Margaret on one of those little sofas that are measured to hold two women when the fashions are moderate, and are wide enough for a woman and one man, whatever happens.

Indeed they must be, since otherwise no one would tolerate them in a drawing-room.
When two women instal themselves in one, and a man is present, it means that he is to go away, because they are either going to make confidences or are going to fight.
Logotheti thought it would be simpler and more tactful to go at once, since Lady Maud was in a hurry, having stopped on her way to the play, presumably in the hope of seeing Margaret alone.