Semper Mine. Sons of War, #1

A standalone novel in the Sons of War contemporary military romance series .Tormented by the loss of his men, Marine Corps Captain Sawyer Mathis returns home to attend a retreat for children who had lost a parent in war. He's forced to spend time with Katya Khavalov, the sister of one of the Marines killed during a firefight under his command. Unafraid of war or death, Sawyer is determined not to let a beautiful woman with a quick temper and broken heart deter him from trying to help her family heal.
Fiery yet sweet Katya resents the cool, unflappable commander. He brought one brother back in a box and the other dismembered. She blames him for destroying her family and believes him to be incapable of feeling anything - until she witnesses firsthand the toll the war and deaths are taking on Sawyer. He's suffering, too, and too stubborn to admit it. The longer the two spend together, the more they begin to understand each other.
What neither is counting on: the feelings they ignite within each other.