To Defend and Honor (Book 1: SIG Series)
Lori Landis

FBI Agent Mac Dresden has spent the past two years colliding with Quinn McBride. She has a unique knack for honing in on his cases. The only way to control her is to include her in his Special Investigations Group (SIG) task force.
With the head of the militia wanting revenge against Quinn, Mac and his team travel to remote New Hampshire to defend the one woman who can help bring in the leader, and who has somehow wormed her way into Mac's heart.
What they don't know is that someone else wants revenge, and they are closer to home than the SIG team knows.