Paco Obregón originally auditioned for the role of Himmler in episode 3: The Ministry of Time: Cómo se reescribe el tiempo (2015). He lost the role to David Luque, but the casting team was so impressed he was offered the role of Abraham Leví, which means he came in to play a Nazi and ended up playing a rabbi.

Michelle Jenner and Eusebio Poncela reprise their roles of Isabella the Catholic and Francisco Jiménez de Cisneros from the series Isabel (2011). The cameo was recorded on the same stage sets as Isabel (2011) before they were dismantled. Rodolfo Sancho played Ferdinand The Catholic on the same series.

The newspaper that Amelia's father reads in 1880 ("Diari Catalá") was the first periodic publication printed in the Catalan language.

The throne room scene was filmed on the set of Isabel (2011), right before it was dismantled.

Michelle Jenner and Eusebio Poncela reprise the roles they had in Javier Olivares' previous production, Isabel (2011), as Queen Isabel and Cisneros.

The music in the scene where Levi heals young Isabel's injured hand is Isabel's motif in the series Isabel (2011).

Episode title: "Bargaining in time"

In this episode Ernesto's identity is revealed, but not to the other characters.