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.

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

Pablo goes into hiding as the political tide turns against him, but he finds a way to strike back. Murphy and Peña finally get the CIA to help them.

A tragic mistake forces the government to change tactics in the fight against Pablo. But Pablo faces bigger threats from inside his empire.

The hunt for Pablo seems to be over after he makes a deal with the government, but Murphy and Peña – and the Cali Cartel – have other plans.

Pablo's activities in prison provoke the government into taking extreme action. Murphy and Peña face a situation of their own.