Nephilim--humans with direct lines to the angels--are natural demon hunters. All nephilim, it seems, except Cassiel. The weakest among a family touched by archangels, she's abandoned her angelic inheritance for a mundane life as a bookseller. But even in the noise of the city, she remains burdened by the strict tenets of her old life. And recently, something far more sinister haunts her.

Avitue is a succubus out for revenge--though she has little say in the matter. As part of the greater demons' plan to ruin Cassiel's family for slaying a duke of Hell, Avitue's been sent to claim a particular nephilim soul, one she's told will pose little challenge. It should be an easy seduction. Quick, fatal. But Avitue is surprised to find her own pain reflected in Cassiel, a nephilim deemed fallen by her own family's standards.

By choosing trust, they reveal the lies that bind them, but as unwilling participants in an eternal war, trusting each other is the most dangerous thing they can do.