The look he shoots her sideways suggests she should know what Abigail Widdowson said about the fae.

"She clearly wanted fae magic re-classified, her own situation must be what drives her. She even went so far as to mention--"

Norrell cuts off, pauses and lowers his glass a fraction as he thinks before focusing on Sylvia.

"She mentioned John Dee's Treatise on Acceptable Magic. Dee has some good ideas, of course, but he is mystical and romantic -- relies too much on fae. She mentioned owning a copy. If... she owns books which exalt the use of fae magic..."