I can't tell what.

She goes out less than ever, and seems to dislike my leaving her." Lucia longed to say, "She has some trouble; some heavy anxiety; can you guess what it is ?" but she had an instinctive consciousness, that even to this dear and tried friend, she ought not to speak of a subject on which Mrs.Costello was invariably silent.

Even to herself, a certain darkness hung over her mother's past life; there were years of it of which she felt utterly ignorant.
Whatever was the cloud of the present, it might be connected with the recollections of those years; this thought checked her even while she spoke.
Whether Maurice had any similar reason for reticence or not, he only said, "I do not think she would hide anything from you which need give you uneasiness.

I advise you not to torment yourself causelessly." "I am not tormenting myself; but I think yours is a miserable plan.

You would have people feel no sympathy for the troubles of others, unless they can be paraded in so many words." "Decidedly you must be very tired, or you would take the trouble to understand me better." He put down his whip, to draw her cloak more closely round her, for the dewy night air was chill, but she pushed it away.
"I am quite warm, thank you.