Silent Surrender by Rita Herron

Tough, jaded Adam Black was the best cop in Savannah. And the loneliest. All work and no play made for empty days and nights until a dark-haired beauty appeared in his office and aroused his passion — and his curiosity — with a bizarre tale that no one would believe. Sarah Cutter had heard a woman being kidnapped from the mysterious Nighthawk Island research center after she’d been living in silence for years. So when the mysterious kidnappers targeted Sarah next, Adam had to risk it all to protect her from harm as he struggled to contain the desire that might threaten to consume them both...