Chilean drug chemist Cockroach brings his product to Colombian smuggler Pablo Escobar. DEA agent Steve Murphy joins the war on drugs in Bogota.

Communist radical group M-19 makes a move against the narcos, while Murphy gets an education in Colombian law enforcement from his new partner Peña.

Murphy encounters the depths of government corruption when he and Peña try to derail Escobar's political ambitions by proving he's a narco.

Despite a new extradition treaty, the U.S. puts more money into fighting communism, creating new challenges for Murphy and Peña in the hunt for Pablo.

Pablo's extreme methods put the narcos on the brink of war with Carillo and the government. Peña tries to protect his witness, Elisa.

Peña and Carillo close in on Gacha, while Murphy tries to protect pro-extradition candidate Gaviria from a notorious assassin connected to Pablo.