Broken Vow (Brutal Birthright, #5) by Sophie Lark

He'll protect her…whether she likes it or not.

Riona Griffin is gorgeous, intelligent, and iron-willed, determined to carve her name in the family ledger without a man at her side. But when she barely survives an unexpected attack on her life, her family hires Raylan Boone as her bodyguard—a rancher, a soldier, and a southern boy with plenty of charm to burn.

And Riona hates his guts.

She doesn't think she needs anybody, but Raylan is pretty sure she needs him. After all, she's being hunted by an assassin who never misses his mark. To keep her safe, Raylan will have to stay by her side, day and night, for the foreseeable future. Riona might think that's a fate worse than death, but once they're alone on Raylan's family ranch, the chemistry between them comes to a boil—and everything changes.

Raylan knows Riona could learn to love him. But he'll have to keep her alive first.

And this hitman isn't getting his girl without a fight.