“Men Against Fire” is one of the better episodes of the series, I think, because it actually featured a sharp twist with a message, and one that wasn’t as obvious as the show’s usual sermons (technology: bad, mob mentality: bad, brain implants: v. v. bad). Stripe (Malachi Kirby) is a soldier fighting in what appears to be Eastern Europe, only the enemy forces he’s targeting are zombie-like mutants known as “roaches.” After a band of roaches raid a nearby village in search of food, the American soldiers pay a visit to a local eccentric who’s believed to be helping the mutants out of a belief that all life is sacred. Searching through some hidden rooms in his house, Stripe encounters several aggressive roaches and kills two, but not before one of them shines a mysterious light in his face that causes his brain implant, or “mass” (a device that allows his commanding officer to transfer visual information to him instantaneously), to start acting peculiarly.
After the ringing in his head affects his performance at a shooting range, Stripe reports to medical, and is sent to a unit psychiatrist (Michael Kelly), who quizzes him on what it felt like to kill the roaches, and how he’s coping. The next day, while infiltrating a roach compound, Stripe is shocked when he sees his fellow soldiers murdering civilians, all of whom seem to be pleading for their lives. He helps a woman escape with her young son, and learns the truth: the implant in his head causes him to see ordinary people as gruesome mutants, and to interpret their peaceable actions as violent ones that threaten his life.
It’s a terrific, unexpected twist, mostly because it seems so plausible: What could be more enticing to an advanced military power than a device that allows soldiers to kill without suffering any guilt or emotional repercussions? In a horrifying conversation in Stripe’s cell after he’s recaptured, the psychiatrist reveals that the technology was pioneered because humans are “genuinely empathetic as a species. We don’t want to kill each other, which is a good thing, until your future depends on wiping out the enemy.” The blood sickness the soldiers were taught to believe was the reason for eliminating the roaches is actually their genetic differentiation, the doctor explains: higher rates of cancer and muscular dystrophy, substandard IQ, higher criminal tendencies and sexual deviance.
With this unexpected lurch toward the subject of eugenics, “Man Against Fire” alludes to a wealth of different prejudices still rife among humankind, particularly institutionalized racism, tribalism, and fear of refugees (the villagers don’t see the roaches as other, it’s worth noting—they’ve simply been taught to see them that way). And it veers into darker territory still toward the end, when Stripe is adamant he doesn’t want his mass reset, and the doctor informs him that if he refuses, he’ll be forced to relive his murder of the two “roaches” on a permanent loop via the implant while he sits in a jail cell. It’s the kind of particularly inconceivable psychological torture Black Mirror likes to throw out once in a while, like being stuck in a log cabin alone listening to Christmas music for what feels like several million years. And it persuades Stripe: At the end of the episode, he’s shown returning home in uniform to a ramshackle house and a woman who most likely is an illusion created by his device.