Grim Port by Aya DeAniege

It was supposed to be the trip of a lifetime.
Little did Cae know, there were forces at work when she visited the land of her ancestors. She arrives in Scotland with romantic notions of discovering long-lost relatives and her great-great-grandmother’s history, and an explanation of how a poor Scottish lass came to own a necklace and a ring of emerald and silver.
Drest was sent to Glasgow on a run. Retrieve a couple of items, talk to some people, and get out before any human is the wiser. But when he stumbles on Cae in the Bloody Dam, he finds himself drawn to the woman—and the jewelry she wears.
It was supposed to be a quiet night, but the universe has other plans.