She owed him that much, at least.

So when Kitty, making an effort to speak quite naturally, mentioned that Peter had been obliged to return to town unexpectedly, she accepted the news with an assumption of naturalness as good as Kitty's own.

Half an hour later, leaving Nan to dress, Kitty departed with any suspicions she might have had entirely lulled.
But her heart ached for the man whose haggard, stern-set face, when he had told her last night that he must go, had conveyed all, and more, than his brief words of explanation.
"Must you really go, Peter ?" she had asked him wistfully.

"I thought--you told me once--that you didn't mean to break off your friendship?
.

.