Stain of Midnight - Heart of Darkness, #2

Darkness is falling, and only werewolves Sonja and Cameron can stop the spread of the stain of midnight before it corrupts everything they love. Lone wolf and metaphysical fixer Sonja Carter has danced on the fence between the supernatural superpowers for years. She's earned a reputation as the one to call when Tacoma's paranormal population finds a situation they can't out-weird. When her former boyfriend Derek, a dark wolf created by a malevolent ritual, loses control of his inner beast, he turns to Sonja for help.
Saving him draws her into a web of magic and evil beyond any she has ever known. Maybe she's never needed the pack, but the pack - and its enforcer - need her. Pack enforcer Cameron Roswell has an axe to grind with the vampire who corrupted his packmates with twisted magics. Cameron means to exact some old-fashioned justice on the one responsible just as soon as the pack can find him. Then troubling dreams grip the enforcer just before the sacrificial murder of a member of his pack, and Cameron wonders if the threat is even greater than he could have realized.
To understand the danger that threatens those he loves, he'll need help from the one woman he's never been able to understand at all.