San Junipero is the LGBT-themed episode of Black Mirror.
The setting at first appears to be a vibrant California-like beach resort town, San Junipero, in 1987. A shy, sheltered young woman, Yorkie (Mackenzie Davis), is visiting San Junipero for the first time, and she awkwardly enters a crowded local bar called Tucker's. Suddenly, Kelly (Gugu Mbatha-Raw), a vivacious party girl, sits next to Yorkie, pretending the two are friends to try to ditch Wes, a man Kelly once had a fling with. Kelly gets Wes to leave by saying she needs to spend quality time with Yorkie, who only has five months left to live. Kelly and Yorkie then get to know each other for real. Their sexual tension rises until Kelly invites Yorkie to dance and Yorkie begins but, increasingly embarrassed, runs out of the bar. When Kelly comes after her and offers to have sex with her, Yorkie tells Kelly she is engaged to a man named Greg. This does not stop Kelly's advances, but Yorkie, though clearly interested, finally walks away.
The following week, Yorkie tries on an array of stereotypically flamboyant '80s styles before giving up and returning to the bar. She again spots Kelly, who is flirting with a new man until she and Yorkie reunite in the bathroom. Yorkie now tells Kelly she is ready, and they kiss and go to Kelly's bungalow to have sex. Yorkie reveals it is the first time she has had sex with anyone, male or female, and Kelly reveals that she was once married to a man for a long time and is bisexual. The scene ends as the clock turns to midnight.
The following week, Yorkie searches for, but cannot find, Kelly. Spotting Wes, Yorkie asks him where Kelly is, but his only advice is to "try a different time" and that he has "seen her in '80, the '90s, 2002 one time". Yorkie then spends the following weeks in those times, searching for Kelly. She eventually finds her in 2002, at a club playing Dance Dance Revolution. Kelly brushes her off, and Yorkie, who is hurt, tells her off. A frustrated Kelly punches a mirror, and the shattered glass instantly repairs itself. Feeling bad, Kelly finds Yorkie and confesses that, in reality, she is dying and only intended to have fun without making a genuine connection with anyone in San Junipero. The two sleep together again, and Kelly tells Yorkie she wants to meet her in real life. Yorkie demurs, but at Kelly's urging tells Kelly her location.
In the present-day real world of the 2040s, the consciousnesses of the dead or dying can be uploaded into a simulated reality system, where they can live in the fantasy town of San Junipero as their younger selves forever. Living people can visit San Junipero for trial periods but are limited to five hours a week. An elderly Kelly (Denise Burse) lives in an assisted living facility, dying of cancer. She goes to visit the real-world Yorkie, who is a completely paralyzed woman surviving via life support. Yorkie became paralyzed over 40 years earlier when her parents rejected her for being a lesbian and she consequently ran her car off the road.
The technology for San Junipero is relatively recent and has now given Yorkie a chance to live a full life again; her plan is to be euthanized and spend her afterlife inside the virtual reality system: a technological process called "passing over". Because her family has religious objections to signing the papers allowing her to be unplugged from life support, she plans on legally marrying Greg, her nurse, so that he may officially override their authority. Upon learning of this, Kelly spontaneously requests a few minutes' visit with Yorkie in San Junipero, where she proposes marriage in Greg's stead, and Yorkie enthusiastically accepts. They wed, and Kelly then authorizes Yorkie's euthanasia, which takes place a few hours after the wedding.
Yorkie passes over happily into San Junipero but is frustrated that Kelly is only able to join her for five hours per week. She asks Kelly to join her full-time in the afterlife, but Kelly rejects this. Kelly's plan is to die without being uploaded to the San Junipero system, as her beloved husband chose to do after 49 years of marriage, himself ruined by the premature death of their adult daughter. Kelly thus wishes to honour her husband's sentiments and die naturally, like him. Within San Junipero, she and Yorkie argue about this until Kelly drives away, deliberately crashes her Jeep, and is thrown from the vehicle. Yorkie arrives, but Kelly's weekly time is up at the very same moment, and her virtual younger body disappears.
Time passes and Kelly's real-life condition worsens. Finally, she changes her mind and opts to live in the San Junipero afterlife, where she and Yorkie can remain together and live happily, forever. Her real-world body is buried with her husband's and daughter's. In a mid-credits scene, a corporation known as TCKR Systems operates a massive server room, wherein robots maintain the consciousnesses of those who now live permanently in San Junipero.
Brooker wrote "San Junipero" after wanting to write a period episode and being inspired by nostalgia therapy for older people. In the initial draft, the love story was between a heterosexual couple, but Brooker changed it. He revealed that he thought this gave the episode an extra resonance, because same-sex marriage was not legal in 1987. Brooker revealed that the song, "Heaven Is a Place on Earth" by Belinda Carlisle (which plays at the beginning and again over the end credits of the episode), was included after he heard it on a 1987 playlist in Spotify, after he had started writing the script. He knew the song would be perfect for the end scene and admitted he would have been "absolutely distraught" if they had been unable to use it.