16-year-old Clare Michaels has always known the truth - that she is the daughter of a fallen angel. That truth has made her life hell. She has spent her entire life running from the children of the fallen. A secret, centuries-old war has divided her kind, and there are only two options if the others find her - join the fight or die. Clare's only ally in her running is her mother, Ellen. They have always hidden in large cities away where they could blend and disappear. So when Ellen decides to move Clare to the tiny town of King's Cross - Ellen's hometown - Clare is skeptical. But King's Cross ends up being more dangerous than even she could imagine.

A dark creature is stalking the locals, Clare keeps hearing the thoughts of someone determined to kill her, and a boy in her class named Daniel seems absolutely determined to become her friend. Clare is not certain which of the three is worse.

But Daniel may be the key to understand her angelic heritage, save lives, and come to grips with her destiny as a Watcher.