Serial Burn by Lynette Eason

She’s out for justice. But the arsonist she’s tracking is out for retribution.

Now the fire marshal of Lake City, Jesslyn McCormick is determined to find the person who started the fire that robbed her of her family when she was just seven years old. As the twentieth anniversary of the tragedy approaches, a string of fires–including at Jesslyn’s church–brings up all those old feelings and offers new evidence.
Because church fires are considered a hate crime, FBI Special Agent Nathan Carlisle is called in to work with local law enforcement. Nathan has his own past–one he’d prefer not to revisit. And focusing on helping Jesslyn track down the arsonist is a great distraction.

As both the case and the chemistry between Jesslyn and Nathan heat up, memories will come flooding in from the past to bump up against hopes for the future. And when Jesslyn comes face-to-face with her worst nightmare, she’ll have to confront her fears and rely on Nathan and her community of friends in order to survive.