For the first time, too, Anna could not say to Rex what was continually in her mind. Perhaps it might have been a pain which she would have had to conceal, that he should so soon care for some one else more than for herself, if such a feeling had not been thoroughly neutralized by doubt and anxiety on his behalf. 
For the first time, Anna could not tell Rex what was in her mind: she had to conceal her doubt and anxiety on his behalf. 