Vengeance is Mine. The Freedom Series, #2

Dina Rodriguez cut her first tooth on trouble. Born to parents embroiled in one of the most secretive CIA operations on the Mexican border, she's seen the dark side of her late father's efforts to keep America safe. The Rodriguez ranch straddles one of the best smuggling corridors in Mexico. Until now, they've maintained an uneasy truce with the drug cartels, but when Juana Altamirez disappears, trouble descends like a six-taloned buzzard.
Juana's husband Raul has been Dina's mentor and friend since childhood, so when he leaves to search the vast canyons of the Sierra Madre for his kidnapped wife, Dina starts her own perilous journey of discovery. She pleads with her husband for help, but with an agent mired in the most daring and dangerous infiltration of his career, Frederick is once more unable to respond to Dina's need. Is this the end of their already tumultuous marriage? Dina has to decide.