My Reluctant Highlander by Nancy Lee Badger
Skye has spent the last five years trying to forget the blacksmith who followed her back to 16th century Scotland, to help fight evil. Sending Jake Jamison home against his will was a disastrous mistake. She risked everything attempting to defeat Andreas Borthwick. Jake might have defeated the evil sorcerer, preventing her husband's death. When she prevents the sorcerer from grabbing her nephew, he takes her instead. To escape, she defies time to find Jake.
The last person Jake wants to see is the young woman from ancient Scotland; the same woman who has haunted his dreams since she blackmailed him into traveling back in time. Before he could save Skye Gunn's people, she had sent him home. Until he met Skye, his life had been normal. Quiet, and uncomplicated. No one knows he is a firebreather, except her. His ancestry is a mystery. When Skye falls into his bed-beaten, bloody and beautiful-Jake must choose to trust her, or turn his back on the only woman he's loved across time.
Skye encourages Jake to use his ability to help her kill the sorcerer. Stealing his heart was not part of the plan. Jake must share his secret, Skye must give her heart fully, and both must dare to love in the time they have.