half-disdainful word concealed a deeper meaning

The old man was attentive to his guests, but the shallowest observer could have scarcely failed to notice his watchfulness of Aurora. It was ever present in his careworn face, that tender, anxious glance which turned to her at every pause in the conversation, and could scarcely withdraw itself from her for the common courtesies of life. If she spoke, he listened — listened as if every careless, half-disdainful word concealed a deeper meaning, which it was his task to discern and unravel. If she was silent, he watched her still more closely, seeking perhaps to penetrate that gloomy veil which sometimes spread itself over her handsome face.
Talbot Bulstrode was not so absorbed by his conversation with Lucy and Mrs. Alexander as to overlook this peculiarity in the father’s manner toward his only child. He saw, too, that when Aurora addressed the banker, it was no longer with that listless indifference, half weariness, half disdain, which seemed natural to her on other occasions. The eager watchfulness of Archibald Floyd was in some measure reflected in his daughter; by fits and starts, it is true, for she generally sank back into that moody abstraction which Captain Bulstrode had observed on the night of the ball; but still it was there, the same feeling as her father’s, though less constant and intense — a watchful, anxious, half-sorrowful affection, which could scarcely exist except under abnormal circumstances. Talbot Bulstrode was vexed to find himself wondering about this, and growing every moment less and less attentive to Lucy’s simple talk.
“What does it mean?” he thought; “has she fallen in love with some man whom her father has forbidden her to marry, and is the old man trying to atone for his severity? That’s scarcely likely. A woman with a head and throat like hers could scarcely fail to be ambitious — ambitious and revengeful, rather than over-susceptible of any tender passion. Did she lose half her fortune upon that race she talked to me about? I’ll ask her presently. Perhaps they have taken away her betting-book, or lamed her favorite horse, or shot some pet dog, to cure him of distemper. She is a spoiled child, of course, this heiress, and I dare say her father would try to get a copy of the moon made for her if she cried for that planet.”
After luncheon, the banker took his guests into the gardens that stretched far away upon two sides of the house — the gardens which poor Eliza Floyd had helped to plan nineteen years before.
Talbot Bulstrode walked rather stiffly from his Crimean wound, but Mrs. Alexander and her daughter suited their pace to his, while Aurora walked before them with her father and Mr. Maldon, and with the mastiff close at her side.