Update 07/18/2016: After watching this no less than 3 times since the initial post here, it really is one of the best. Bumped to A+ from A-.
How can US law enforcement make a serious dent in the operations of Mexican drug cartels? Plan a major hit against a top cartel boss and force his organisation to dismantle. Confidently directed with a tight focused story and excellent performances this makes for a very good movie. It is more that that though. It’s told primarily as the story of FBI agent Mercer, played by Emily Blunt in another great role. Mercer is enlisted to help on this nebulous mission by…someone. It’s a tough environment she is thrown into with the cartel from one side and her mysterious new commander played by Josh Brolin on the other side. She is not even sure who he really is, let alone who his right-hand man, Alejandro, is. She keeps up, gets banged up and learns a few things along the way. It’s a film that brings us along and expects us to keep up just like Mercer.