Wil A. Emerson 
Under Cover [EPUB ebook] 

Jonathan Lopez, an ex-intelligence officer with deteriorating eyesight, wakes to unsettling noises in his isolated cabin. With his gun ready, he prepares to confront an intruder, fearing for the safety of his partner Beth and their dog Homer. As he stealthily investigates, he discovers not a threat but a terrified, malnourished teenage girl, who has escaped human traffickers. Determined to bring her captors to justice, Jonathan finds a new purpose in tracking down the criminals.