His Obsession Next Door (In the Line of Duty, #1)

Once the fuse is lit, there's only one way to extinguish the flames.

Years ago, Cole Sullivan made a battlefield promise sealed in a dying man's blood—to take care of his best friend's little sister. Now he's forced to live with the fact that Gemma Matthews is completely off limits.

Though Gemma's always had a crush on the darkly handsome, far-too-serious explosives expert, she can't forget the sting of his rejection. Now here they are, ten years later, with Cole still stubbornly in the role ...