Elaine's Apartment Ward

Mouse finally stopped at a door, and I extended my hand, half closing my eyes, feeling for magic. There was a ward over the door. It wasn't terribly fancy or solid - it couldn't be, without a threshold to use as a foundation - but it was exceedingly well crafted and I was sure it was Elaine's work. The spell looked like it would release only a tiny bit of energy, probably a pulse of light or some kind of audible sound that would alert her to company.

White Night Chapter 18, Page 172