"I don't want any one here to know that I have gone to London."

Catherine thought a moment.

"I know you are not going to give me your reasons," she said, after a
pause. "But why do you tell me there is a secret?"

"Because you are trustworthy."

"Why do tell _me_ that you are going to London?"

"Because you must be prepared to act in an emergency."

"Mother, what do you mean?"

"I will tell you enough of my meaning to guide you, my love. I have had
some news that troubles me. I am going to London to try and put some
wrong things right. You need not look so horrified, Kate; I shall
certainly put them right. It might complicate matters in certain
quarters if it were known that I had gone to London, therefore I do it
secretly. It is necessary, however, that one person should know where to
write to me. I choose you to be that person, Catherine, but you are only
to send me a letter in case of need."

"If we are ill, or anything of that sort, mother?"

"Nothing of that sort. You and Mabel are in superb health. I am not
going to prepare for any such unlikely contingency as your sudden
illness. Catherine, these are the _only_ circumstances under which
you are to communicate with your mother. Listen, my dear daughter.