The series is an "after the end" retelling of Sleeping Beauty, beginning at the moment when Aurora wakes up. Her family are all dead, her "true love" is a stranger, and the entire world has changed while she slept.
In A Wicked Thing, Aurora was my Sansa Stark-esque heroine, trapped in an impossible situation and trying to survive. In Kingdom of Ashes, she has a lot more freedom -- and a lot more room to screw things up. She's exploring the world, experimenting with her magic, and being entranced by the dragons she believes may hold the answers to her powers.
And, you know, she's also flirting with princes. Because what's a fantasy adventure without a little slow-burn romance?
You can read the first seven chapters of Kingdom of Ashes for free here.