Fae magic! Tridents! Norrell feels increasingly distressed by all this news, and it shows as his face begins to furrow deeper into discontent.

"Well what if they followed you here! What if it was a trap!" Since for all his confidence in his wards five minutes ago, the prospect of fae with tridents coming to his house is suddenly making him uneasy. He lunges for a book, begins to flick through for something uneasily. "Did they give you anything, Childermass? Slip something into your pockets? Why would they not kill you?"

A trap, surely! A way to bypass his wards!