Saving Annie Grace — Bruce Weiss

 Annie Grace and her two young student interns travel to a remote area of the Andes to work at an archeological dig site. Annie's hope is that the team can discover the 'Andean-Inca' Rosetta Stone so the ancient Inca language can finally be interpreted and explained. The work looks promising until they are kidnapped and transported to one of the largest coca growing plantations in the Andes. As prisoners, they become a pawn between a drug lord ready to harvest, and the US government with plans to destroy the fields before they can be harvested. 

 This is a compelling novel where human lives and an entire empire are at stake. Annie and her young women are doomed unless they can be saved by someone.