My main complaint about this book is the title and the cover. They make it look like one of the latest and trendiest teen romance novels. However, if you can get past what the book looks like, the actual story is an intriguing, steampunk, alternate history with great allusions to Doctor Jekyl and Mister Hyde. There is a slight romance, but it stays within the appropriate boundaries of Victorian England gentility (one, maybe two kisses). The story and world building are the focus of the novel. In spite of the look of the book, it is a good (and very clean) teen fantasy read.
Finley Jayne (okay, my other complaint is the heroine's name-great character but trendy and not very Victorian name) knows she has a darker side to her personality. When she is angry or afraid, that personality comes out with its astonishing strength and thirst for danger. However, when Finley fights a young lord who is trying to take advantage of her, she knows her darker side is leading her toward trouble unless she can control it.
Soon after, Finley meets Griffin King, a duke who holds special powers himself. He recognizes Finley's powers as an asset and promises he can teach her to control them. Griffin and his friends take Finley in and together they work to fight a criminal called the Machinist. Their strange powers may be the only hope against a mad villain working to take over Victorian England.