In a holy walled city where sin and sanctity are revealed through touch, Csilla - a girl born without a soul - is worth little to the Church that raised her. But when a series of murders corrodes the faithful magic that keep the city safe, the Church elders see a use for her flaw: she can assassinate their prime suspect, a heretic with divine heritage, without risking the stain of sin.

The heretic, however, makes Csilla a counteroffer: clear his name by helping him catch the real killer, and he'll use his angelic gifts to grant her very own soul. Meanwhile, ruthless Ilan, desperate to earn back his position as Church Inquisitor, sees the case as his chance at redemption: he'll bring in the murderer - or, failing that, Csilla and the heretic - and regain his title.

But as the death toll rises, and their hunt pits them against the all-powerful and callous Faith, Csilla finds herself torn. Will her salvation come at the cost of everything she believes in?