It is 1518. A group of Spanish conquistadores land in Yucatan Peninsula and fight against the natives, with natives and Spaniards dying as the former retreat back into the jungle. The conquistador leader takes his men into the natives' town and orders them to murder them, only for them to find two Spaniards among the local Mayans, one of them the tribe's main warrior, Gonzalo Guerrero
. He cuts the Conquistador leader on the cheek, and orders them to leave and never return to America.
In the present, there is trouble: Francisco de Aguilar has not met with Hernán Cortés as expected, and this puts in jeopardy Hernán Cortés' conquest of the Aztec Empire. Alonso and Pacino must go there (even though Pacino was looking forward to a concert that was going to take place later in the day - in the 80s) and bring Aguilar to Cortés. In the island of Cozumel, they meet a Ministry agent called Bernal Díaz del Castillo who tells them what they should do - but, without their knowledge, that man turns out to be part of the Ángel Exterminador.
In the Ministry, Lola and Ernesto are discussing Lola's daughter and Lola's relation to her, when every phone rings out. Salvador has received a message: the Sons of Padilla want Pere Folch to be freed, and they are threatening the lives of the Ministry's loved ones (Elena, Ernesto's son, Amelia's mother, Pacino's father and Irene's ex-wife). Salvador orders them to be watched, but Lola points out it is a stratagem to distract the Ministry. Salvador's phone receives a call: it is Marta, who gives Salvador 24 hours to acquiesce with her demands. Of course, the problem is that Pere Folch is dead.
In 1518, while Alonso (who is angry with Guerrero's betrayal of Church and Country) and Pacino reach the Yucatan peninsula, Aguilar is praying when Guerrero comes up to him. It is obvious Guerrero has little if any respect for Christianism ever since the shipwreck that left him, Aguilar and his friends there. And, when Alonso and Pacino arrive to the town's outskirts, they observe that Aguilar is considered the Butt-Monkey. Alonso attempts to go there to pull Aguilar out, but Pacino stops him, pointing out that the Mayans heavily surpass them in number, and that it would be better to wait until night came. Alonso says he misses Amelia.
In the present, Salvador tells Ernesto, Irene and Lola that he does not intend to negotiate with the Sons of Padilla, which they agree with. Marta calls, and Salvador replies that he does not negotiate with terrorists, pointing out that their previous actions are not exactly origami. Marta hangs up, and it is revealed that she has something big in hand: she and her accomplice are in 1956, and they have taken nine year old Salvador.
Back in 1518, Alonso and Pacino sneak into the Mayans' town, but as soon as Pacino awakens Aguilar, they are caught by Guerrero and the Mayan warriors, who put them in a cage. Guerrero takes Pacino's intertime cellular (which Pacino claims is a compass) and binoculars and leaves them to spend the night. Alonso and Pacino argue, and the latter admits he is scared of dying so far away from his time and place. The following day, Guerrero comes and asks for their names: when Alonso gives his, Guerrero asks if he is related to Gaspar de Entrerríos, but Alonso manages to divert the question - as the man is his grandfather, and the reason he became a soldier.
In the present, Irene reveals there is a number of Ministry agents that went missing and were considered deceased, all of whom may actually be part of the Sons of Padilla. Lola points out that they might have some relation with the men that worked with Leiva in his attempted takeover of the Ministry, but before they can do much else, Salvador begins to choke up - at the same time his younger self chokes in the past.
In 1518, Guerrero has allowed Alonso and Pacino to leave the cage, and that he is convincing the tribe's cacique to let them leave with Aguilar, telling them what happened to him and Aguilar: after their ship wrecked against the Yucatan's coast, the survivors were found by a tribe that sacrificed and ate most of them. Only Guerrero and Aguilar managed to escape, only to be found by this tribe, which enslaved them. Guerrero got the cacique to free him after saving him from a caiman, and after the conquistadores' attack they also freed Aguilar.
In 1956, Marta's accomplice takes photos of young Salvador to further threaten the present Ministry, but Marta is starting to feel doubts about their actions. Meanwhile, present Salvador is in a coma, which the doctor mentions must have been induced by eating a lot of peanuts, to which Salvador is allergic: Lola realizes the symptoms agree with the possibility that young Salvador ate a normal dose of peanuts. Ernesto and Lola go to 1956 to find out where Salvador is after Angustias finds out Marta adopted Salvador from the orphanage.
Back in 1518, Guerrero is trying to convince Alonso to teach the tribe how to fight, but the Tercio veteran is not keen on the idea and asks Guerrero why he left everything behind: Guerrero points out that all of his fighting only serves kings and generals, while the soldiers are left with nothing. Outside, Aguilar is attacked by the children and gets angry. This starts a fight in which first Pacino, then Alonso get involved in order to protect Aguilar, with Alonso sparing the life of one of the Mayans.
Again to 1956, Ernesto (as a police detective) and Lola (as a nun) meet the San Ildefonso school's director to gain a description of the people that adopted Salvador, saying they are child robbers. The woman is easily identified as Marta, and Lola recognizes the description of the man as one of those former agents who were thought dead (and, as an extra, he followed the original Padilla as well).
In 1518, Alonso and Pacino are again in jail, but they are soon freed, as the tribe's cacique consider Alonso's actions to save Aguilar and spare the warrior (who is the cacique's son) noble. The tribe invites the duo to have dinner and tobacco, and Guerrero gives them the good news: the two of them, along with Aguilar, may leave the following day.
In 1956, young Salvador is still very ill, and Marta begins to realize the child does not deserve to die.
In 1518, Aguilar, Alonso and Pacino are welcomed to the Spanish camp by Bernal, and they are brought before Gaspar de Entrerríos, Alonso's grandfather and also the man whose cheek Guerrero cut earlier. Much to Alonso's disappointment, Gaspar is only interested in gold and gaining an encomienda, having abandoned his wife and son in Spain. He also wants to return to the town in order to kill Guerrero in revenge for the cut.
In 1956, Marta has taken young Salvador to a hospital, and Irene calls Ernesto with the news - but Marta's accomplice also learns about it by calling one of his partners.
In 1518, night has fallen, and Aguilar meets with Alonso and Pacino. Alonso feels very disappointed with his grandfather, and Aguilar shares the news that Bernal is an impostor, as he met the real deal a few years before. Aguilar also wants to save Guerrero from Gaspar, but they cannot warn him nor summon some help.
In 1956, Marta's accomplice has found her and Salvador, and he points a gun at her, saying the Sons' Great Council has ordered him to kill both her and young Salvador. Marta asks for a moment to say goodbye to Salvador, but she surreptitiously manages to grab a gun she has hidden and kills her accomplice. Before she can escape, though, she crosses paths with Ernesto and Lola, and Marta decides to surrender.
In 1518, Guerrero uses Pacino's binoculars to see the conquistadores coming to the beach, and sets up a trap for them: the town is empty, and when the conquistadores come in, he has the tribe's archers surround them. When Entrerríos threatens to murder a Mayan child, Guerrero offers him a duel: if Entrerríos wins, he'll be free to do whatever he wants, but if Guerrero wins then Entrerríos will leave and never return. Entrerríos agrees, and a duel ensues, which Guerrero wins. However, the false Bernal brings out a modern handgun and points it at Guerrero with the obvious intention of killing him: Alonso jumps on him, but the gun fires and the bullet kills Gaspar de Entrerríos. A fight ensues, and the Mayans fire their arrows at the conquistadores, leaving only Alonso and Pacino alive.
In the present, Salvador is now restored, and warns Irene and Ernesto not to tell Pacino Marta has been captured. Salvador gifts Pacino with two tickets to a David Bowie concert, and tells Alonso in private that he has not changed history, because his grandfather would have died later that year anyway - but Alonso is still affected by the fact that his grandfather was not like he had believed.
