Highlander’s Fearless Angel by Isobel Irving

Protecting her means laying his soul bare. But she is the only one who can save his future — and that of his clan…

Peigi MacLean grew up sheltered in a convent and always dreamed of marrying for love. But when she finds out that the man she promised to wed is a dangerous liar, Peigi has no choice: to save herself from a terrible fate, she must run away.

Trained to kill when just a boy, Lucas Kincaid is a jaded warrior with a scarred body to match his tattered soul. Though he usually only draws his weapon for coin, when Lucas happens upon Peigi struggling to resist kidnap by her wicked suitor, Lucas defends the beautiful lass, securing her safety by posing as her husband.
While Peigi is grateful to Lucas, she will not change her plans: she wants to travel onwards alone, and the weary mercenary cannot convince the strong-willed lass otherwise. But leaving the innocent girl unprotected in the wilds of the Highlands would be to condemn her to death. So despite her protests, Lucas escorts Peigi.

Forced to travel together, Peigi softens towards the brawny warrior, melting his defenses, and Lucas shares a painful tale he has told no one before: his birthright was to become a clan chieftain, but his evil uncle stole his title. Peigi wants to help him regain his true position as laird, but Lucas refuses to face what he has been running from all his life.
Yet Peigi can never forget Lucas’s kindness towards her. So with enemies closing in on them both, the bold lass will risk everything to fight for her savior, and a last battle will take place, not only for their lives, but for their hearts…