Contains spoilers for this episode and earlier episodes.
The killings of Colombian officers force Pinzón out of the operation and persuade Gaviria to bring Horacio Carrillo back from Madrid. Murphy and Peña welcome a commander who has frightened Pablo before, hoping his return will restore momentum. Carrillo promises smaller, more discreet operations, then makes a public incursion into Pablo's neighbourhood to expose the lookouts who report police movements.
The police round up children working as spotters. Carrillo shoots one boy and sends another back to Pablo with a cartridge and a warning. Peña sees the killing and struggles with the methods being used in their name. Pablo turns the surviving child's account into a weapon against Carrillo, arranging for the accusation to be broadcast and trying to weaken the man now pursuing him.
Judy Moncada also works against Pablo, using information about a laboratory to draw the authorities toward his men. A raid captures suspects, and Murphy insists on joining Carrillo rather than being kept away from the violent work. A helicopter interrogation ends with captives thrown to their deaths. The experience leaves Murphy shaken enough to telephone Connie in Miami. Carrillo's return has produced arrests and frightened the cartel, but it has also drawn both DEA partners into killings they cannot dismiss as ordinary police work.