Throne of the Fallen (Prince of Sin, 1) by Kerri Maniscalco

Sinner. Villain. Wicked. The Prince of Envy has never claimed to be a saint. But when a cryptic note arrives, signaling the beginning of a deadly game, he knows it will take more than a hint of sin to win and save his falling demon court. Riddles, hexed objects, anonymous players, nothing will stand in his way, though none of his meticulous plans prepare him for her, the frustrating artist who ignites his sin like no other… Virtuous. Darling. Liar. The trouble with scoundrels and blackguards is that they haven’t a modicum of honor, a fact Miss Camilla Antonius learns after one desperate mistake allows Waverly Green’s most notorious rake to blackmail her. To avoid a ruinous scandal, Camilla is forced to enter a devil’s bargain with Envy, little expecting his game will awaken her true nature . . . Together, Envy and Camilla must embark on a perilous journey through the Underworld—from glittering demon courts to the sultry vampire realm and beyond—while trying to avoid the most dangerous trap of all: falling in love.