With her childhood demon banished, Aria Tate has plans to settle into a comfortable routine with her shop and continue growing her relationship with Jeremy. However, the ever closer approach of her brother's first full moon, a stranger claiming to be her brother, and a shadowy organization called the Sentries trying to recruit Jeremy say quiet isn't in her future no matter how much she wants. As she tries to navigate a world of town secrets and family lies, Aria finds herself learning about an age old promise that reveals the dark and twisted origins of her family's magic. If she wants a shot at normalcy ever again, she just might have to make a deal with the devil, but what if she's not entirely sure who the devil is?