This is the first episode in the series that neither features a historical event nor a historical person as a character.
"El tiempo en sus manos" ("The time on his hands") is the Spanish localized title of The Time Machine (1960).
The plot was inspired by the so-called "Murder House" in Antonio Grilo St 3, Madrid. This building is infamous for the high number of violent deaths that have happened there or nearby, including murders, suicides and accidents since 1909 at least.
Episode title: "The time on his hands"