Rather it was a new and bewildering problem.

That it was the immediate cause of her mother's illness was evident enough, but why?
Who was "C."?
Why did she fear his return?
What could be the fear strong enough to induce such precautions for secrecy?
Her senses seemed utterly confused.

But after the first few minutes, she remembered that Mrs.
Costello had probably meant to keep her still ignorant of a mystery to which she had, in all the recollections of her life, no single clue--she might therefore be still further agitated by knowing that she had read this letter.

"I must put it aside," she thought, "and not tell her until she is well again." She slipped the letter into her pocket, scribbled her note to Mrs.
Scott, and returned to the invalid's room.

The faintness had now quite passed away, and Lucia thought, as she entered, that her mother's eyes turned to her with a peculiar look of inquiry.