Having been alone at home, in the bedroom only because it was the only room with any actual furnishings, reading a heavy book about math theorems, Lydia hadn't been expecting a knock right outside the door. Nor had she been expecting a cheerfully British voice calling out to her.
She was surprised enough that she actually screamed, the heavy crash of the book falling to the floor clearly heard through the house.
She was on her feet a second later, the bedroom door flying open a second after that, staring crossly at the ghost. "When I said come by, I assumed you'd be a normal person and ring the doorbell or something."