Is "Black Mirror" one universe, or are call backs to previous episodes simply ‘Easter eggs’ left by creator Charlie Brooker to reward a loyal fan base?

Prior to the Netflix exclusive release of the 4^th season of "Black Mirror", the most popular theory was that "Black Mirror" did not simply exist in one universe. Rather that the reoccurrences, like the trial of Victoria Skillane, or the song “Anyone Who Knows What Love Is (would understand)”, were simply callbacks to other episodes without actually connecting the episodes. "Black Mirror" existed in a “Twilight Zone” reality in which multiple universes overlapped and weaved together in an impossible to decipher entanglement, and each episode stood alone. After watching the finale of season 4, “Black Museum”, fans are saying the ‘Easter egg’ argument can no longer be made.

Season 4 was littered with the usual callbacks; a comic book entitled "15 Million Merits" referencing the episode of the same name, the mention of the television show within the show "Hot Shots", numerous references to the cartoon character Waldo, and of course the song that seems to link nearly every episode “Anyone Who Knows What Love Is (Will Understand)”. The finale forced all episodes into a singular universe by jamming the episode with physical objects representing previous characters, actions, and technologies

In “Black Museum” viewers are shown that nearly every episode of the season had a common theme: crimes, and that a Museum existed celebrating and showcasing every crime from the season as well as crimes from previous seasons. Objects from each crime were on display in the museum; a bathtub from “Crocodile”, the Archangel tablet, a lollypop from “USS Callister”.

The episode did not simply stop the linkage between episodes of the crimes though. The overarching theme of "Black Mirror" as an entire series is that of technology, and “Black Museum” once and for all linked all that technology together, allowing us to trace which technology came first. It established a single world in which we can piece together a chronological order of episodes for the first time.

"Black Mirror" Episodes in chronological order:

"Fifteen Million Merits"

"Men Against Fire"

"The Waldo Moment"

"The National Anthem & Be Right Back"

"Shut up and Dance" & "Playtest"

"White Bear"

"Hang the DJ"

"USS Callister"

"Arkangel"

"Nosedive"

"White Christmas"

"Hated in the Nation"

"Crocodile"

"San Junipero"

"The Entire History of You"

"Black Museum"

"Metal Head"

The chronology has been established through the evolving technology and clues littered in episodes. Previously fans have stated that there is no way the episodes can exist in the same universe due to the vast differences between technologies where technologies are equally advanced but very different.

While at first this makes sense, we must think about how technology functions, it gets used and then after a while it gets phased out, allowing new technology to take its place which too will eventually be phased out and replaced. The trends in technology are typically short-lived, even in the "Black Mirror" universe.

"Fifteen Million Merits"

“Fifteen Million Merits” must come first due to the numerous references to the character of Abi, “Anyone Who Knows What Love Is (Will Understand)”, "Wraith Babes"and "Hot Shots" that come in later episodes.

To begin, “Fifteen Million Merits” must be placed ahead of “Men Against Fire” due to the voice of Abi singing “Anyone Who Knows What Love Is (Will Understand)” in “Men Against Fire. “Fifteen Million Merits” must also come before “The Waldo Moment” due to Abi being on a billboard meaning she is already famous, so the story of “Fifteen Million Merits” has already happened by the time the story of “The Waldo Moment” begins.

The argument is often made that this cannot possibly be true and that “Fifteen Million Merits” must be far in the future due to the strange society they take part of, but the evidence of Abi on the billboard disproves this. There are various theories as to why the society of “Fifteen Million Merits” exists the way it does; it is a prison system, or the way another country handles their poor, or the way overpopulation is being handled, whichever theory fans choose to subscribe to the timeline of “Fifteen Million Merits” is clear.

"Men Against Fire"

“Men Against Fire” seems to come next, since it must be placed above “The National Anthem”, due to a headline in the episode referring to the main character of “The National Anthem”, Michael Callow, as the Prime Minister. This is a title we can reason he no longer holds after the story of “The National Anthem” concludes. Since the headline is not a reference to the news story that is the main plot of “The National Anthem”, we can conclude that “Men Against Fire” must take place before it.

Though it may seem the technology, the MASS system, in “Men Against Fire” is advanced and it should be placed later due to the MASS system, the argument can be made that currently the technology is strictly military technology but later will become available to the public as we see in "White Christmas","The Entire History of You", and "Arkangel".

"The Waldo Moment"

We know that “The National Anthem” must come after “Men Against Fire”, and can conclude that “The National Anthem”, “Be Right Back”, and “The Waldo Moment” must all be happening around the same time due to the same news headline: “Geraint Fitch cleared of wrongdoing following paparazzi scuffle” popping up in all three episodes. Logically “The Waldo Moment” happened right before “The National Anthem” began, otherwise it would only make sense that Waldo, a comedian who thrives on the sort of scandal taking place in "The National Anthem", would mention it at some point. Since he makes no reference, we can reason that the story of “The National Anthem” has not occurred yet.

"The National Anthem" & "Be Right Back"

Due to the headline mentioning Fitch, the time difference between “The National Anthem” and “Be Right Back” appears to be nonexistent. Though the technology in “Be Right Back” at first may appear to be significantly more advanced than that of “The National Anthem” and “The Waldo Moment”, everything the main character, Martha, uses in “Be Right Back” is a prototype. She appears to be part of an experimental trial of technology that is not available to the public, or publicly discussed, otherwise she would not be able to lock her android husband in the attic. Based on the way “Be Right Back” ends, we can assume the trials did not go well overall and the technology was never widely available since we never see it again.

"Shut Up and Dance" & "Playtest"

“Shut Up and Dance” seems to occur next, alongside “Playtest”, with chronology being so close between the two that they could essentially be happening at the same time. We can reason this knowing “Shut Up and Dance” must come after “The Waldo Moment”, which occurs around the same time as “The National Anthem” and “Be Right Back”, since there is a username that references Waldo in “Shut Up and Dance”. “Shut up and Dance” needs to come earlier than nearly every other episode due to the large jump technology makes in other episodes.

“Playtest” seems to fall around the same time as “Shut Up and Dance”. While “Playtest” does feature an advancement in technology, the advancement entirely is behind closed doors and is still in the experimental phase, none of the technology is available to the public-similar to "Be Right Back". When the characters of “Playtest” are not using the experimental technology in a secret location, they use similar cell phones to those in both “Shut Up and Dance” and “Hang The DJ”. In “Playtest” the main character also uses a dating app on his phone, which is the main plot to “Hang The DJ”, but in “Playtest” the interphase of the dating app is completely different. The “Playtest” dating app is a Tinder style app in which the user swipes left or right, which is nothing compared to the sophisticated technology of the dating app seen in “Hang The DJ”, placing “Playtest” chronologically earlier than “Hang The DJ”.

"White Bear"

The main way to place “White Bear” chronologically is by looking at the sheer number of episodes with references to it. We know that “White Bear” takes place before “Hated in the Nation” through discussions characters have. There are also various hashtags throughout “Hated in the Nation”, like #Freethewhitebearone, that place “White Bear” previous to it. “White Christmas” shows the headline “Victoria Skillane appeal bid rejected”, showing that the goings on of “White Bear” happened before “White Christmas”.

If we look at the technology in “White Bear” as well as references from other episodes, we can piece together that it cannot be too far forward in the timeline. People are recording on their phones, the technology is nowhere near what it becomes in “White Christmas”. The phones people are recording with are not as advanced as those in "Nosedive", rather they are closer to that of “Hang The DJ”, though the slightest bit lower tech. Since previously the murder trial, which was one of the biggest in the country, was not referenced on any news networks or internet searches in previous episodes, we can assume it had not happened yet, placing “White Bear” after those all previously mentioned episodes chronologically.

"Hang The DJ"

In “Hang The DJ”, the two main characters use a dating app on their cell phones, the dating app uses simulation technology. The use of simulations, rather than utilization of the technology of Cookies is what grounds the episode chronologically. Cookies logically would do the work more accurately than a simulation, since Cookies are exact replicas of individuals rather than a just simulation of the individual. So, if the technology of Cookies existed it would make no logical sense to still be using the outdated technology of simulations to make matches, leading to the conclusion that “Hang The DJ” takes place pre-Cookies. It would also reason that it would take place pre-Reputelligent, from “Nosedive”, otherwise that would also be used in place of simulation or at least be taken into account.

"USS Callister"

Both “Hang the DJ” and “USS Callister” take place around the same time, and mostly in simulations. We can confirm they are taking place close in time, because the dating app that makes up the plot of “Hang the DJ” is used by the receptionist in “USS Callister”. This allows us to apply the same logic to the chronological placement, using the lines of technology.

Along the lines of technology, things are more advanced in “USS Callister” than they are in previous episodes. The technology used to upload the personalities to The Cloud appears to be a more primitive and rougher version of Cookies. The crew of the USS Callister never reference Cookies and seem shocked by the technology, signifying the technology of the “USS Callister” comes before Cookies.

We also know that “USS Callister” must take place before “Crocodile”. The same pizza delivery service appears in both episodes, in “USS Callister” a pizza delivery man comes to deliver the pizza and in “Crocodile” a self-driven pizza truck delivers pizza, signifying an advancement in technology pushing "Crocodile" later in time. .

"Arkangel"

“Arkangel” features a large leap in technology, but another one in which the technology is purely experimental, though unlike the previous experiments with technology the people surrounding the main character are aware of the technology the main character posesses. The Arkangel system appears to be an early prototype of Grain and Z-Eye technologies featured in “The Entire History of You” and “ White Christmas”. The Arkangel technology is not available to the public though, and during the episode due to ethical problems the project ends up getting scrapped entirely as a system for monitoring children. The experiment must preclude Grain and Z-Eye due to other character responses to Arkangel. The Arkangel system may be the first attempt to integrate the MASS system, from "Men Against Fire" away from just military use and into use of the general public.

This clearly places "Arkangel" before both “White Christmas”, which features Z-Eye technology, and “The Entire History of You.” It is worth noting, that the interphase with the rewind feature on the Arkangel is nearly identical to the interphase of Grain, though Grain can be taken out which Arkangel cannot.

"Nosedive"

“Nosedive” is a hard one to peg, because the idea of rating people as an all-encompassing system of life seems like a far cry away from technology or social norms of any other episodes. In actuality, this episode illustrates the point that trends in technology, in this case the technology system being Reputelligent, go in and out quickly in the "Black Mirror" universe. We can first establish that “Nosedive” takes place after “The National Anthem” due to a headline referring to the main character of "The National Anthem" in the episode.

We can also say without a doubt that it is after “Hang The DJ” and “Playtest”, the advancement in the technology of the cell phones tell us this. The phones look different, they are thinner and the back shines through in “Nosedive”, which we do not see in previous episodes.

Possibly more importantly, we can say for certain that “Nosedive” takes place before “Hated in The Nation” in which a headline is shown that says “Reputelligent takes nosedive.” This illustrates the idea of technology becoming totally obsolete in the "Black Mirror" universe, killing the argument that says the universe must be separate due to the differences in technology, or technology being used in one episode but not another.

"White Christmas"

“White Christmas” marks a large jump in technology with the idea of Cookies being introduced and the Z-Eye blocking technology coming into play. Though we can reasonably say that this jump in technology occurred quickly considering that one of the main characters uses computers like ones we use today, and are used in previous episodes, in flashbacks of the episode while he also uses the Z-Eye.

While Cookies come up in later episodes, this is the earliest introduction of them. The consciousnesses in the Cookies are treated badly in “White Christmas”, as we see by the way Greta’s cookie is treated and by the way the police treat Joe’s cookie. The police can do this because the cookies are not considered humans, it is not until “Hated in the Nation” that the headline pops up declaring that Cookies have been granted human rights. This helps us to place “White Christmas” before “Hated in the Nation.”

Z-Eye shows that “White Christmas” happens before “The Entire History of You”. Z-Eye appears to be a primitive version of the Grain technology in “The Entire History of You”. While the blocking technology and the way the Z-Eye functions are very similar to Grain, the Grain system is much more sophisticated. Grain has fast forward and rewind options and by the time “The Entire History of You” takes place the technology has advanced to where it can be removed if people choose, something not available in “White Christmas” through the Z-Eye.

"Hated in the Nation"

It could reasonably be said that “White Christmas” and “Hated in the Nation” take place closely together. They share many similar news headlines, in “White Christmas” a news bullet shows up referencing Victoria Skillane from “White Bear”, and her appeal being rejected. In “Hated in the Nation” it is shown that Skillane is trending on social media, though it says nothing about her bid pending, which it reasonably would if her bid had not already been rejected. It also references Skillane and a suicide attempt, pointing to the fact that she likely tried to take her own life after her bid was rejected. These details reasonably place “Hated in the Nation” after “White Christmas”.

Cookies are granted human rights by the time “Hated in the Nation” takes place, while they had no rights in “White Christmas” which is clear from the interrogation practices and time lengthening used on the Cookie.

It is also likely that “Hated in the Nation” takes place before “Crocodile”, since during the course of the investigation they never use any technology like ‘The Recaller’ to help them solve things more efficiently, nor do they in "White Christmas".

"Crocodile"

The main technology in “Crocodile” comes in the form of The Recaller, a device that allows someone to view other people’s memories. This likely places “Crocodile” after “White Christmas”, because if this technology existed in “White Christmas” the police could simply view Joe’s memories instead of creating a Cookie version of him and tricking a confession out of him. This would be both cheaper, and more effective.

With all of the death in “Crocodile” the idea of uploading consciousness is never brought up by any of the characters, which likely means that it does not exist yet. This means “Crocodile” takes place before “San Junipero”.

"San Junipero"

“San Junipero” is predictably late chronologically. The technology involved is extremely advanced, Cookies have essentially been phased out in favor of uploading the entire self. The technology has built upon itself to allow the advanced world of San Junipero where your uploading self stays alive, and young, even after you are dead. The technology of the episode essentially defeats death by using the basic idea of Cookies and building upon it to develop the most advanced technology yet. San Junipero is referenced in both “Black Museum” through clothing and direct quotes and “Metalhead” through the use of a postcard, coming before each of them.

"Black Museum"

The episode in so heavily laden with references it is easy to place near the chronological end. The episode essentially serves as a museum of past episodes, putting them on display as things past. Every crime committed, every piece of technology, even characters from previous episodes, are exhibits in “Black Museum.” The episode makes it impossible to avoid that all the stories take place in the same universe, and that "Black Museum" serves to both preserve their stories and act as a chronological landmark.

A photo of Victoria Skillane from “White Bear”, the 'Double Suicide' headline referencing White Christmas, the bathtub from “Crocodile”, a bee from “Hated in the Nation”, the lollypop from the USS Callister, Dresses worn by characters in “San Junipero”, the tablet from “Arkangel”, the suicide from “The National Anthem”, and the headset from “Playtest” make up a few of the exhibits in the museum, placing all of these episodes clearly chronologically before "Black Museum".

The story also illustrates a technological timeline in which we see how the technology featured in "San Junipero" was created, as well as other technologies from throughout Black Mirror. The only technology that does not seem to be referenced in "Black Museum" is Grain, this seems to place Grain technology and thus “The Entire History of You” after “Black Museum”.

"The Entire History of You"

The Episode comes as one of the latest due to the sheer advancement in technology. The MASS system, was built upon and became the prototype featured in "Arkangel". The Arkangel system failed due to ethics issues, but the technology allowed for the development of Z-Eye for the public, which ultimately leads to Grain technology.

“The Entire History of You” is placed later than “Black Museum” due to Grain being just about the only technology not referenced in the episode. In an episode so heavily laden with references, this does not seem like a mistake and leads to the conclusion that “The Entire History of You”, must take place after “Black Museum”.

While the technology of Grain is powerful, and allows people to record, replay, and capture their entire lives the technology does not seem to make people very happy. Perhaps it even played a part in whatever caused society to collapse leading to the post-apocalyptic world we see in "Metalhead".

"Metalhead"

This is clearly the farthest forward in the Black Mirror universe as it a post-apocalyptic waste land, taken over by robots. The episode features little technology, other than tiny robots referred to as ‘Dogs’. It is clear that society as we know it has collapsed and there is no need for ranking systems, Recallers, and even if they had Grains (which they might) they would not want to play anything back. The technology that built up the Black Mirror universe is essentially rendered useless, and at the end of the timeline we are left with desperate people clinging to the most basic aspects of humanity. This is truly the overarching theme of "Black Mirror" as a series, the idea of the fragility of humanity even with the most advanced technology. "Metalhead" serves to prove that even after everything, every crime, every plot, every piece of technology, in the end only humanity matters.