A large fleet is anchored in the port of Lisbon, in 1588: it is the Grande y Felicísima Armada (the Invincible Armada), ready to leave on its fated, unsuccessful attempt to invade England. One man walks along the port to the recruitment office and grabs a bunch of papers to file them. He notices there is something wrong with the San Juan's crew list, and, after confirming the list is complete, he rushes to his room... where he grabs a laptop and a hand scanner, which he uses to send a message to the 2015 Ministry. Turns out there is a name missing from the list, that of future famous playwright and poet Lope de Vega. If Lope de Vega does not board that ship (one of the few that managed to return to Spain without losses), he runs the risk of dying in another ship. As Amelia is a noted expert in Lope de Vega, Salvador orders her, Alonso and Julián to travel to 1588 with one objective: get Lope de Vega on the San Juan.
Once in Lisbon (the doors can take people to a time and place that was Spanish territory) it does not take the team long in finding Lope de Vega: true to his Really Gets Around self, he is fighting with another man over a Portuguese lady while reciting verses from Orlando Furioso (which Amelia mentioned in the previous episode was an influence in his early works). However, when he sets eyes on Amelia, Lope leaves the Portuguese woman and comes to flirt with Amelia, even after Julián states he is her husband (and reciting his own "poem", a stanza of an 80's rock song).
During their research, the team - aided by the 1588 Ministry agent, Gil Pérez - finds out that Lope has enlisted in the San Esteban, one of the ships that were sunk, but the surprise comes when they find another name in the lists: Alonso de Entrerríos, surprising Alonso and setting him on the path of finding out who is masquerading as him. His surprise is great when he finds out it is an eighteen-year-old boy that claims he is joining the Armada to follow on his father's footsteps, a man he never knew but who he has been told was a war hero. Alonso soon realizes that his wife Blanca wanted to tell him she was pregnant when she visited him in prison the day he was recruited by the Ministry: the teenager is his son, and he is enroled in another ship that will sink.
Amelia gets seduced by Lope, even after she sees through his blatant attempt to "rescue" her from a bunch of robbers, and willingly sleeps with him. Julián goes to Lope's room and knocks the writer out in just two hits, before telling Amelia off for being so naïve to fall for Lope's charms, also pointing out the risks she is taking in sleeping with a man from another time, no matter how much she might idolize him. However, now that they have secured Lope, they have a problem: instead of Alonso, the one they meet near the door is a knocked-out Alonso Jr. Amelia and Julián rush to find their companion, who drunkenly tells them he won't allow his son to die, willingly taking his place in the ship. Julián cuts him off by knocking him out - and preventing trouble by offering the other sailors money if they help them take Alonso to his ship - and bringing him to the gate.
The next morning, Lope de Vega wakes up with a headache and is told by Gil Pérez that the ship he had been expected to join has already left. This, normally, entails being condemned to death, but Gil Pérez offers him the alternative of joining the San Juan's crew, where a few spots have opened after the turmoil of the previous night. Right behind him is Alonso de Entrerríos Junior, who gets offered the same choice, with one task: making sure that Lope will board the ship.
With the mission fulfilled, and history saved again, Alonso travels to 1578, to visit his son at age eight, giving him a bag of money and telling him to give it to his mother, saying he is "an old friend".
