Read it through once

In his brief letter to her he had made no allusion to M. Rivière's visit, and his intention had been to bury the incident in his bosom. But her reminder that they were in his wife's carriage provoked him to an impulse of retaliation. He would see if she liked his reference to Rivière any better than he liked hers to May! As on certain other occasions when he had expected to shake her out of her usual composure, she betrayed no sign of surprise: and at once he concluded: "He writes to her, then."