Shadow Trace (Shadow Alliance #4)
Shawna Coleing

But the scientist is not who he expects and when the innocuous threat turns out to be real, his careless attitude toward his latest assignment means he nearly loses the person he is supposed to be protecting. Now, Aaron’s biggest problem is figuring out who to trust, and after discovering that a biological weapon is in danger of being stolen, everyone around him has a convincing motive, including the woman he’s falling for.