Deception of a Highlander by Madeline Martin

Mariel Brandon has been forced to become a spy for one of England’s most ruthless underground thugs, but her new assignment is more than she can bear: she must become an assassin. With her brother being used as bait to make her compliant, she has no choice but to comply. However, she does not expect the man she must kill to stir such feelings and passion within her. And yet, how can she not when his death is the only thing that can save her brother?
Kieran MacDonald, Laird of the MacDonald clan, has his suspicions about the English, most especially the lovely lass who has suddenly taken an interest in him and has insisted he escort her to Scotland. She’s far too beautiful, far too interested in him…and he is far too tempted. While he longs for the freedom to take her as he so fiercely desires, he has his own secrets that must be safeguarded.
With a line drawn between love and family, and life and death, hard decisions must be made and no answer offers a way for everyone to remain safe. When sacrifice and desperation clash, how far can love and passion truly go with so much deception at play?