Raven Calls (Walker Papers, #7)

Something wicked this way comes…

Suddenly, being bitten by a werewolf is the least of Joanne Walker's problems.

Her personal life in turmoil, her job as a cop over, she's been called to Ireland by the magic within her. And though Joanne's skills have grown by leaps and bounds, Ireland's magic is old and very powerful….

In fact, this is a case of unfinished business. Because the woman Joanne has come to Ireland to rescue is the woman who sacrificed everything for Joanne—the woman who died a year ago. Now, through a slip in time, she's in thrall to a dark power and Joanne must battle darkness, time and the gods themselves to save her.