Warning: This review contains spoilers forBlack Mirrorseason 6, episode 3, “Beyond the Sea.”

After the silly satire of “Joan is Awful” and the murderous mayhem of “Loch Henry,” the third installment ofBlack Mirror’s latest season – “Beyond the Sea” – takes audiences into outer space for a surprisingly somber, meditative, character-focused drama. Aaron Paul and Josh Hartnett star as a pair of astronauts, Cliff and David, who are able to escape from their mundane mission by transferring their consciousness into cybernetic replicas of themselves down on Earth, allowing them to spend time with their families in between the work. One night, David’s home is invaded by a Manson Family-style hippie cult determined to protect the natural order by dismantling the robotic David and slaughtering his family. David is left to grieve the loss of his wife and kids in almost complete isolation aboard the spaceship, while Cliff tries to figure out a way to pick up his spirits and help him process the unthinkable tragedy.

Kate Mara stands in a field in Black Mirror

“Beyond the Sea” is the longest episode of season 6 with a feature-length runtime of 80 minutes. Director John Crowley gives each scene plenty of room to breathe and takes his time letting the audience get to know the characters and their relationship. Crowley brings that relationship to life, much like he did with the love triangle in his acclaimed featureBrooklyn, but he also has an eye for spectacle. The space sequences in “Beyond the Sea,” in which Cliff goes out to fix broken parts of the ship, are appropriately breathtaking. The eerie silence captures space withthe same haunting sense of realism as2001: A Space Odyssey.

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The Ugliness Of Jealousy

In the opening scenes, Cliff feebly tries to comfort David to no avail. Eventually, Cliff realizes that what David needs is to get out of his own head and be grounded back on Earth. Since David’s replica has been destroyed, Cliff lends David his replica. David gets a new lease on life while embodying Cliff’s replica, wandering around his farm and getting to know his wife, played byHouse of Cards’ Kate Mara. At first, sharing a replica creates a heartwarming bond between the two spacebound colleagues and it seems like this might be another rare example of a nice,lightheartedBlack Mirrorepisode like the iconic “San Junipero.”

However, before too long, David falls for Cliff’s wife and cooks up a nefarious ulterior motive to steal his life. Much like season 1’s “The Entire History of You,” “Beyond the Sea” uses a futuristic technology to explore the ugliness of jealousy. In this case, the jealousy goes both ways: David is envious of what Cliff has with his wife, and Cliff is anxious about losing his wife to another man. This dynamic gives Paul an interesting acting challenge as he has to switch between playing his own character and Hartnett’s character in his replica body. Paul is up to the task, effortlessly conveying which character is which to the audience with subtle mannerisms and speech patterns. Mara has her fair share of challenges, too, playing opposite two characters played by one actor, and she also nails her scenes.

Rory Culkin as a cult leader in Black Mirror

Silent Running Meets Once Upon A Time In Hollywood

With men tending to plants in space and hippies breaking into a private residence, “Beyond the Sea” plays likeSilent RunningmeetsOnce Upon a Time in Hollywood(in a good way). The 1969 setting of “Beyond the Sea,” complete with period-accurate wardrobe and social attitudes, bringsBlack Mirrorback to its roots asan homage toThe Twilight Zone. Hartnett’s guarded, stiff-upper-lip portrayal of David could’ve been ripped straight from an episode of Rod Serling’s original series.

As with all the bestBlack Mirrorepisodes, “Beyond the Sea” builds to a truly harrowing twist ending. And since Crowley has taken the time to round out the characters and make the audience care about them and understand them, that twist ending hits even harder. The replica technology sets up the twist reveal brilliantly, with Cliff returning to his robotic body to find blood all over his hands and the walls of his house. From that moment, it’s obvious what David has done, but Cliff desperately searches the house for his wife and son, holding onto the futile hope that they might still be okay, before breaking down in a pool of their blood in the kitchen.

With a longer runtime and less twist-driven storytelling thanthe averageBlack Mirrorinstallment, it does require some patience to get into “Beyond the Sea.” But once it gets past the shocking inciting incident, this episode tells one of the most touching and humanistic stories thatBlack Mirrorhas ever tackled. Getting to know David and Cliff, following the evolution of their relationship, and being stunned by its violent ending makes “Beyond the Sea” a rich and rewarding viewing experience.