Sebastian takes place in Ephemera, a world affected--literally--by human emotions. To keep things somewhat stable, there are Landscapers who shape the landscape and Bridges, who connect them. And there are wizards and demons and incubi and succubi. The eponymous Sebastian is a half-incubus. Rejected as a child by his wizard father and by other children because of his heritage, he nonetheless experienced love and acceptance during the periods when his father allowed him to stay with his aunt and cousins. Now he lives in a landscape created by ultra-powerful rogue Landscaper Belladonna called the Den of Iniquity with others of his kind and, surprisingly, a pure and innocent young woman, Lynnea, with whom he's falling in love. But the Eater of the World has escaped and is threatening all of Ephemera, and it's up to Sebastian and Belladonna to save the world. The entire story is like a fable, the moral of which is the need for balance. Sebastian's history is one of love balanced by rejection--necessary to mold his character. The Den of Iniquity is just as necessary to Ephemera as Sanctuary, its opposite. Landscapers learn early on that all emotions, not just positive ones, are required to form a stable landscape. Balance is the goal of the characters in the story, even if they don't know it--it's what they need to be whole, complete, and happy. Or put another way, it's about shades of gray. Sebastian and Belladonna are dark heroes, but despite their supernatural abilities, they're dark in a human and understandable way. This is a much lighter book than Bishop's Black Jewels trilogy, which is not to say it's a lesser book, but it's definitely different--and because expectations affect enjoyment so much, don't expect a reprise of Daemon and Jaenelle here. Kudos to Bishop for that, by the way: she wrote an excellent dark fantasy series, and now she's writing something else. I have the next book on my to-buy list. I'm looking forward to it.