Paladin's Faith by T. Kingfisher — book slip

Marguerite Florian has spent her life acquiring and selling information, using whatever means necessary. When she falls afoul of a powerful former employer, her usual methods of self-preservation no longer work.

Fortunately, she has collected enough favors to attempt an audacious scheme to undermine her enemies.

With the service of Shane, a paladin of a dead god and much too handsome for his own good, Marguerite will be forced to navigate a glittering and dangerous court, northern wilds, and the cult of a demon in a brazen attempt to destabilize an entire economy.

Intrigue and violence were to be expected, but is Marguerite prepared for the battle for her soul—and her heart?