Aibhlinn Ultana Smith is your average everyday New Yorker. She enjoys a good cup of coffee, window shopping, and works hard at her job as a CPS worker. Completely normal, except she's not human. She is a changeling, a Fey child who was left with a human family to wreak havoc. Now's she's a grown woman who constantly flits back and forth between the human and the fay's world. One day when she was checking one of the children she looks after she discovers he and several others have been affected by a mysterious illness that doesn't seem to have come from the human world. Making up her mind she goes into the Boston troll market where she gets wrapped up in the beginnings of a war between the human and Fey if the Elven Prince has his way. Now she must not only find out how to deal with this new sickness but try and stop an impending war. What's a Fey girl to do?