Captivated is the first novel in the Donovan legacy, and starts as the series continues - first and foremost it is a traditional romance rather than a romantic thriller as with many of Nora Roberts' deeper stories, and I think this is what lets the book down. Although it is still a readable story and the characters are, as always, thoroughly likeable, there just doesn't seem much to get your teeth into. It's very predictable and follows the basic Roberts formula of personal difficulties getting in the way of the romance, which then have to be worked through etc, and there weren't any of the little surprises or quirks that usually make up a Roberts' narrative.
This would be worthwhile if you are a hard and fast NR fan and already like her fluffier silhouette stories, but if you prefer the deeper romantic thrillers with pace, drama and intrigue as well as romance then I'd say this isn't for you. If it's the idea of witchcraft and magic that interests you then I recommend the 'three sisters trilogy': Dance Upon the Air (1), Heaven and Earth (2) and Face the Fire (3).