The Greats- To Save The World book 4. To Save The World, #4

Twenty-six years after the birth of Drina and Ronan's sons, a new threat arises. Domhnall and Callum, the twin Lairds of the MacInnon clan, must complete a blood bond of their own with a certain woman from their mother's time in order to awaken their powers and defeat the one who seeks to set loose a great darkness upon the world. Rowan Murphy is just a normal gal trying to get through college. A mysterious suitor starts showing up to the diner she works at.
He manages to weasel a couple of harrowing dates out of her, and it quickly becomes clear that she can't remain in her hometown of Fayetteville Arkansas any longer. She jumps at the opportunity to move to Scotland to live with her Aunt Quin, who recently married the modern-day MacInnon Laird. Once there, she's introduced to a world of which she never could've imagined existed in her wildest dreams.
Join this fated trio as they awaken their powers and discover the truth about Rowan's lineage, entrenched in a new and terrifying world where the fae meddle in human affairs and don't take too kindly to half-bloods.