Romeo and Taft approach the rehab center, but a zombie soldier, the Giant, throws a rock at them and the helicopter crashes. Becerril and Cruz give the order and the zombies attack the rehab center. The narcos, led by Chainsaw, fight back. Some zombies die, but most of them don't seem to be affected by the narcos' bullets. Marroquín tries to protect his son, but when a zombie attacks, they get separated. Lucas must run for his life and another zombie is about to kill him when Lilia saves him. Marroquín discovers that Lilia has been recording with a secret phone, but he knows that now is not the time to deal with that. Finally, Marroquín realizes his son was right, these human monsters are not traitors, and that they are the result of a new and powerful drug. Chainsaw survives a zombie attack, but he's seriously wounded and not able to walk. Taft and Romeo survive the helicopter crash and fight the zombies together, but things get complicated when Lucas recognizes Romeo as his lost uncle. Taft and Marroquín agree to a truce. When the rangers from the US Army arrive, Marroquín must escape one more time, and Lucas, Dávila, Romeo and Lilia go with him to the secret tunnel. Becerril tricks Murdoch by pretending to surrender, but then surprises Snowman when he announces that they are much smarter than humans. Using smoke bombs, zombies plot a brilliant escape to the hills. Marroquín is bitten and possibly infected, but he hides his wound from the rest of the group. Snowman finally gets to capture another zombie specimen. While Marroquín takes his son and the rest of the survivors through the dark tunnel, a zombie pig is waiting for them further ahead.
—Amazon Studios