In some way she has come to regard it as a duty to abandon you.

Let Emily once think it a duty, and she will go through with it if it costs her life; so much I know of her; so much it is easy to know, if one has the habit of observing.

May I advise you?
Do not try to see her again, but write briefly, asking her whether the mystery she spoke of in any way connects itself with you.

You will know how to put it so as to exact the answer you require.

Suppose you write such a note at once; I will send it as soon as it is ready.