Among the show's established perimeters is that travel can only go into the past. It's not possible to go to the future, because, as is the secret Ministry's motto, "Time is what it is." So, while the ministry has also continued into the future since the days the doors were discovered and mapped and the equations to use them were worked out by a combination of 16th C Moorish, Jewish and -- I think, still not sure -- Jesuits, the ministry, like Spain, continues.
In our own present time the location is mostly Madrid, however the Ministry's the employees are from different times. They can travel to what the time is in Ministry HQ, because the HQ is in now. The Ministry's mission is to keep the past from being changed, to preserve the existence of Spain, no matter how good or how bad.
The fun part is the variety of historical figures of Spain's past, particularly its Siglo de Oro (though just how golden the century was really, at least in Europe, with the Ottomans beating their's, the Holy Roman Empire, the Venetian and others' butts all the time, particularly in the Mediterranean -- not to mention the English with the Armada). The notable historical figures include even fictionally created personages from the 16th century.
The show's new swordsman-recruit from the 16th century, Alonso de Entrerríos, discovers in the present the novels of Arturo Pérez-Reverte's Captain Alatriste. In our time, many who encounter Entrerríos just assume he's Captain Alatriste -- since I like and admire the Alatriste novels, I love this series's bit.
The series mixes a generally light treatment with more serious matters, without beating the viewer down with the more grave elements. It's an excellent way to make Spain's national history real to the viewer too, no matter what age. It would be good family viewing, I think, without talking down to the audience either.
Our first period adventure was preventing French time travelers, with the aid of a beautiful but of course corrupt Spanish -- countess? duquessa? -- from changing the history of the guerrilla warfare that contributed so much to Napoleon's failure in Spain, from which he continued to failure in Russia, etc. Upcoming events include what may be a Spanish whitewashing of history -- to keep Spain out of WWII. Right now I'm in the middle of trying to keep Lope de Vega from sailing with the Armada and dying before he wrote his great works, that helped make the 16th century, in this sense at least, Spain's Golden Century.
Already though I have learned that the principle three characters' more personal concerns from their own times get mixed up with their historical missions. The show does an elegant job of showing us just how impossible it is to not to mix the personal with the historical, the present with the past, even in the past -- though this is prohibited to all employees of the Ministry.
The writers do an equally excellent job of getting quickly past the by-now-to-we-jaded sf/f readers info dumps about how and why and introduction of characters to their new lives in the past and present. They cut to the chase with the most minimum of O What Is This!
One does wish Netflix USA did more Spanish television series
(particularly Isabella, which I am dying to watch) -- Spain does historicals so very well -- the horse riding and sword fighting in particular! I have gotten more than tired of the endless Asian sword and sorcery, whether live action or anime -- there's such a damned glut, and it's all the same.
The series also sued NBC for ripping it off -- see here, the lawsuit the Spanish producers filed about Timeless. Once one has watched even the pilot for El Ministerio del Tiempo, it's pretty hard not to be disgusted with NBC utterly shameless behavior -- the characters are even the same, particularly the group leader who is a young female historian.