In a world divided by blood, the Red serve the elite Silver-blooded, who wield supernatural powers. Mare Barrow, a Red thief scraping by, suddenly finds herself thrust into the opulent heart of the Silver court.

When Mare discovers she harbors a dangerous ability of her own, the king forces her into a web of lies, masquerading as a lost Silver princess and betrothed to his son. Torn between her new life and her roots, Mare secretly joins the Scarlet Guard, a Red rebellion igniting beneath the surface.

As treachery lurks around every corner and her heart is pulled in conflicting directions, Mare must decide how far she's willing to go. In a deadly game where the only certainty is betrayal, will she spark the revolution, or will darkness consume her?