Scrying for Summer by Katherine Mcintyre

Jev was looking for an adventure, however she wanted the usual variety of stomping out nasty fae in the city as an enforcer of the Philly Coven. Instead, handsome-as-sin Liam O’Reilly shows up on her doorstep dropping news of the worst organization of fae they’d dealt with on the rise again. Except, he’s a traitor, an asshole, and the absolute last person she wants to work with.
However, the longer they work together, the more the fire between them burns, turning from rage and irritation into something primal. And as she gets to know the real Liam O’Reilly behind the charming smiles and sexy lines, he becomes so much deadlier. Because the protective, self-sacrificing man underneath the facade is just the sort she could fall for.