Lincoln Zane has faced dangerous assignments before, but none quite like this. His newest mission? Protect Isabel Maddox, his boss’s fiery, fiercely independent sister, from a faceless threat. When the situation gets too hot to handle, Lincoln does what any good security specialist would—he takes her to a safe house. But Isabel isn’t exactly the damsel in distress type, and she's not thrilled about being cooped up with Mr. Tough-and-Taciturn. Sparks fly (and not just from the danger) as they work together to figure out who's after her. Between trying to crack the case and keeping their growing chemistry in check, Lincoln realizes that keeping Isabel safe might be the easiest part of the job—keeping his heart out of it is another story entirely.