Song of a Highlander by Katy Baker

To find her future she must travel to the past.
Jessica Maxwell cannot believe her bad luck. The research paper that should have made her career has turned her into a laughing stock, her funding grant is about to run out, and someone has ransacked her lab.
So when a strange old woman appears from nowhere to warn her that her research has put her in danger from fairy tale creatures from the distant past, she’s sure her day can’t get much worse. She’s wrong.
Ramsay MacAuley is a man out of his time. Having been banished to the future by a perilous bargain with the Fae, he is determined to protect the secrets of time. But when he stumbles across a woman who knows far more than she should and both are sent hurtling into the past, he realizes it is not mere chance that has thrown her into his path – and he must protect her with his life.
Beset by enemies on all sides, Jess and Ramsay must find a way back to the future if they are to stop ancient evil from claiming the power of time. But as Jess finds herself drawn to the enigmatic warrior, she begins to wonder if the future is where she wants to be at all.