Premise: She therefore opened the desk, and in searching for the stamps she came across something else ”that slip of paper which Dorcas saw in her hand, and which assuredly was never meant for Mrs. Inglethorp's eyes.
Hypothesis: Dorcas found a document that Mrs. Inglethorp was never meant to see while searching for stamps in the desk, so she hid it where she would never find it. 
Label: neutral