Handlingen foregår i Praha, i en verden man aldri før har sett. Rundt om i verden dukker det opp håndavtrykk som er brent inn i helt vanlige dører. I en mørk og støvete butikk har en djevels beholdning av mennesketenner blitt faretruende liten. Og i de trange smugene i Praha er Karou, en ung kunststudent i søken etter sin egen ukjente historie, i ferd med å bli fanget i en brutal krig med vesener fra en parallell verden. Da en av de fremmede - vakre, forfulgte Akiva - setter øynene i henne i en bakgate i Marrakesh, befinner hun seg snart i en krig mellom engler og demoner, hemmeligheter kommer for dagen og en kjærlighetshistorie med røtter i en brutal fortid oppstår. Men det spørs om Karou kommer til å angre på at hun søkte sannheten om seg selv.
Errand requiring immediate attention. Come. The note was on vellum, pierced by the talons of the almost-crow that delivered it. Karou read the message. 'He never says please', she sighed, but she gathered up her things. When Brimstone called, she always came. In general, Karou has managed to keep her two lives in balance. On the one hand, she's a seventeen-year-old art student in Prague; on the other, errand-girl to a monstrous creature who is the closest thing she has to family. Raised half in our world, half in 'Elsewhere', she has never understood Brimstone's dark work - buying teeth from hunters and murderers - nor how she came into his keeping. She is a secret even to herself, plagued by the sensation that she isn't whole. Now the doors to Elsewhere are closing, and Karou must choose between the safety of her human life and the dangers of a war-ravaged world that may hold the answers she has always sought. 'Remarkable and beautifully written ...The opening volume of a truly original trilogy.' GUARDIAN