Cursed Luck by Kelley Armstrong

Kennedy Bennett comes from a long line of curse weavers. For centuries, her family has plied their trade in Unstable, Massachusetts, a quirky small town that’s welcomed paranormal practitioners since the dawn of spiritualism. Kennedy has recently struck out on her own, opening an antiques shop in Boston, where her speciality is uncursing and reselling hexed objects.

Then Aiden Connolly walks into her life with an offer she really should refuse. The scion of a wealthy family of luck workers, Aiden has a scheme to get his hands on the most famous cursed object of all: the mythical Necklace of Harmonia. He’s not the only one after the necklace, though. And he’s not the only one looking for a curse weaver to fix it. Kennedy’s sisters are kidnapped, she finds herself plunged into the underbelly of the magical world where even Aidan soon finds himself in over his head.