Question: Which is the fourth episode of the tv series "Black Mirror", directed by Owen Harris?
Context: The Mirror Universe is a fictional parallel universe in which the plots of several "Star Trek" television episodes take place.  It resembles the fictional universe in which the "Star Trek" TV series takes place, but is separate from the main universe.  The characters in the Mirror Universe are aggressive, mistrustful, and opportunistic in personality.  Whereas the "Star Trek" universe depicts an optimistic future in which the Earth-based United Federation of Planets values peace, co-operation and exploration, episodes set in the Mirror Universe feature the human-dominated authoritarian Terran Empire which values war, despotism, and conquest instead.  The Mirror Universe has been visited in one episode of "", five episodes of "" and a two-part episode of "" as well as several non-canon "Star Trek" novels and video games.  It is named after "", the episode in which it first appeared. "The Entire History of You" is the third and final episode of the first series of British science fiction anthology series "Black Mirror".  It was written by the creator of "Peep Show" and "Fresh Meat", Jesse Armstrong, making it the only episode of the series not written or co-written by creator and showrunner Charlie Brooker.  It was directed by Brian Welsh, and first aired on Channel 4 on 18 December 2011. "White Bear" is the second episode of the second series of the British science fiction anthology series "Black Mirror".  It was written by the series creator and showrunner Charlie Brooker and directed by Carl Tibbetts.  The episode follows Victoria (Lenora Crichlow), a woman who does not remember who she is and wakes up in a place where almost everybody is controlled by a television signal.  Along with some of the few other unaffected people (Michael Smiley and Tuppence Middleton), she must stop the "White Bear" transmitter while surviving merciless pursuers. He has directed episodes of "Secret Diary of a Call Girl", and "Misfits", and the TV movies "Holy Flying Circus" and "The Gamechangers".  In 2013, he directed "Be Right Back", an episode of the anthology series "Black Mirror", and in 2016 he directed a further episode "San Junipero". The Waldo Moment is the third episode of the second series of British science fiction anthology series "Black Mirror".  It was written by series creator and showrunner Charlie Brooker and directed by Bryn Higgins, and first aired on Channel 4 on 25 February 2013.  The episode originated in an idea for "Nathan Barley", an earlier TV show by Brooker and Chris Morris. "Hated in the Nation" is the sixth and final episode of the third series of British science fiction anthology series "Black Mirror".  Written by series creator and showrunner Charlie Brooker and directed by James Hawes, it premiered on Netflix on 21 October 2016, along with the rest of series three.  It is the longest episode in the series at 89 minutes. "White Christmas" is a 2014 Christmas special episode of the British science fiction anthology series "Black Mirror".  It was written by series creator and showrunner Charlie Brooker and directed by Carl Tibbetts, and first aired on Channel 4 on 16 December 2014.  The only television special of the series, it is also the last episode to be aired on Channel 4, as the series would move to Netflix for its third series. The Gamechangers is a British docudrama produced by the BBC.  The programme depicts the story of the controversy caused by "Grand Theft Auto", a video game series by Rockstar Games, as various attempts were made to halt the production of the games.  Directed by Owen Harris and written by James Wood, the film centres on the legal feud between Rockstar Games president Sam Houser (Daniel Radcliffe) and controversial attorney Jack Thompson (Bill Paxton) over Rockstar's popular video game series "Grand Theft Auto", and the debate regarding the psychological effects of violent video games. "Be Right Back" is the first episode of the second series of British science fiction anthology series "Black Mirror".  It was written by series creator and showrunner Charlie Brooker, directed by Owen Harris and first aired on Channel 4 on 11 February 2013. "San Junipero" is the fourth episode of the third series of British science fiction anthology series "Black Mirror".  Written by series creator and showrunner Charlie Brooker and directed by Owen Harris, it premiered on Netflix on 21 October 2016, together with the rest of series three.  The episode has a substantially happier tone than other "Black Mirror" episodes, and is one of the show's most successful episodes.
Answer: San Junipero