The Kill Season — Robin Mahle

Special Agent Kate Reid still reels after a thinly veiled threat from one of her own. She soon discovers who has her back and who doesn't during their most dangerous investigation yet. The city of Rio de Janeiro is famous for its beautiful beaches and wild nightlife, but there is a dark side tourists don't see. Rio's favelas, or slums, are inhabited by a network of drug lords, human traffickers and dirty cops. And when victims from the largest favela are found buried in the hillside, everyone looks the other way. However, it seems there is one who cares; a cop who suddenly finds a conscience when the mother of one of the missing pleads for help. He begins to unravel clues that point to an American, and with the help of his Inspector, they contact the FBI's International Operations Division for help.It's a murder case the BAU team has no business trying to solve. It's outside their jurisdiction. Except the FBI has offices worldwide and when they're called on by International Ops. in Brazil, they have no choice but to come to their aid. If an American is responsible, they will bring him to justice.Lives are put at risk in a dangerous place. Cracks in the BAU team become chasms. And when the corrupt discover the FBI is in their city, no one knows if they'll make it out alive.