Badlands Witch by Carrie Vaughn

In brand-new stories spun off from the New York Times Bestselling Kitty Norville series, dark mysteries push the bounds of sanity. Cormac Bennett, ex-con and former bounty hunter, is a paranormal investigator with an edge: his partner is the disembodied spirit of a Victorian wizard, Amelia Parker. Together, they solve problems no one else can.

Cormac and Amelia travel to South Dakota, where an archeologist has hired them to examine an artifact for possible magical qualities. Cormac is skeptical, Amelia is intrigued. And it turns out – the whole thing is a trap. Cormac used to make his living killing monsters, and he made more than a few enemies back in the day. Who from his past is out for revenge, and can he and Amelia survive?