Rachel withdrew to the window to keep watch on the park. "Don't hurry," she said. "No signs of her yet."
Mrs. Milroy still paused, keeping the all-important morsel of paper folded in her hand. She could have taken Miss Gwilt's life, but she hesitated at reading Miss Gwilt's letter.
"Are you troubled with scruples?" asked the nurse, with a sneer. "Consider it a duty you owe to your daughter."
"You wretch!" said Mrs. Milroy. With that expression of opinion, she opened the letter.
It was evidently written in great haste, was undated, and was signed in initials only. Thus it ran: "Diana Street.
"BY DEAR LYDIA--The cab is waiting at the door, and I have only a moment to tell you that I am obliged to leave London, on business, for three or four days, or a week at longest. My letters will be forwarded if you write. I got yours yesterday, and I agree with you that it is very important to put him off the awkward subject of yourself and your family as long as you safely can. The better you know him, the better you will be able to make up the sort of story that will do. Once told, you will have to stick to it; and, having to stick to it, beware of making it complicated, and beware of making it in a hurry. I will write again about this, and give you my own ideas. In the meantime, don't risk meeting him too often in the park.
"Yours, M. O."
"Well?" asked the nurse, returning to the bedside. "Have you done with it?"
"Meeting him in the park!" repeated Mrs. Milroy, with her eyes still fastened on the letter. "Him! Rachel, where is the major?"
"In his own room."
"I don't believe it!"
"Have your own way. I want the letter and the envelope."
"Can you close it again so that she won't know?"
"What I can open I can shut. Anything more?"
"Nothing more."
Mrs. Milroy was left alone again, to review her plan of attack by the new light that had now been thrown on Miss Gwilt.
The information that had been gained by opening the governess's letter pointed plainly to the conclusion that an adventuress had stolen her way into the house by means of a false reference. But having been obtained by an act of treachery which it was impossible to acknowledge, it was not information that could be used either for warning the major or for exposing Miss Gwilt. The one available weapon in Mrs. Milroy's hands was the weapon furnished by her own returned letter, and the one question to decide was how to make the best and speediest use of it.