Sentence:  Removing a portion of chair which had got entangled in my back hair, I said with a candour that became me well: “I was looking for a mouse.” If she had replied, “Ah, yes, indeed. I understand now. A mouse, to be sure. Quite,” everything would have been nice and smooth, but she didn't. “A mouse?” she said. “What do you mean?” Well, of course, if she didn't know what a mouse was, there was evidently a good deal of tedious <WSD>spadework</WSD> before us, and one would scarcely have known where to start. 
Meaning of the word marked with <WSD> tags:  Work done in preparation for something else.