There was something so pathetic and so unwonted in Catherine’s tone that Mrs. Bertram was quite touched.  She bent forward, placed her hand under the young chin, raised the handsome face, and printed a kiss on the brow.

“Kitty shall help her mother best by staying at home,” she said.  “Seriously, my love.  I must leave you in charge here.  Not only in charge of the house, of the servants, of Mabel—­but—­of my secret.”

“What secret, mother?”

“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.  Listen attentively.  A good deal depends on your discretion.  A stranger may call.  The stranger may be either a man or a woman.  He or she will ask to see me.  Finding I am away this person, whether man or woman, will try to have an interview with either you or Mabel, and will endeavor by every means to get my address.  Mabel, knowing nothing, can reveal nothing, and you, Kate, you are to put the stranger on the wrong scent, to get rid of the stranger by some means, and immediately to telegraph to me.  My address is in this closed-up envelope.  Lock the envelope in your desk; open it if the contingency to which I have alluded occurs, not otherwise.  And now, my dear child, I must go upstairs and pack.”

Catherine roused herself from her kneeling position with difficulty.  She felt cold and stiff, queer and old.

“Shall I help you, mother,” she asked.

“No, my dear, I shall ring for Clara.  I shall tell Clara that I am going to Manchester.  A train to Manchester can be taken from Fleet-hill Junction, so it will all sound quite natural.  Go out to Mabel, dear.  Tell her any story you like.”

“I don’t tell stories, mother.  I shall have nothing to say to Mabel.”