Charlie Brooker’s been hiding something. Beneath that hugely entertaining mantle of misanthropy and idiocy-skewering invective, beats the charitable heart of a man who wants us all to care a little bit more. If there’s a lesson to White Christmas – a trio of Black Mirror stories about the consequences of loneliness and ostracisation – it would be to stop, think, and empathise. Even, or perhaps especially, with our public demons. White Christmas’ first story introduces us to Matt (Jon Hamm, whose matinee idol good looks cast him perfectly as the kind of swaggering, smug Yank an intensely British drama like Black Mirror would instantly mistrust). Alongside his day job, Matt runs a seedy side-line as a pickup artist coach and wank conductor to a voyeuristic choir of online pervs. Taking Google Glass to its logical conclusion, the world of White Christmas is populated by augmented humans whose Z-Eye implants let them control and share what they see. It’s in this kind of technological advance – one that doesn’t seem far off in the realm of possibility but that has the potential to shatter human relationships – that Black Mirror specialises. Z-Eyes slot in neatly alongside series one’s “Grain” implant from The Entire History Of You, a recording device that let you rewind, rewatch and endlessly revisit any moment from your life (handy if you’ve lost your keys, not so much when you’re paranoically obsessing over your partner’s suspected infidelity). At this point in proceedings, Matt is the villain of the piece. He’s manipulative, deceitful and views people by category and women as safes to crack (the voyeur chorus quickly diagnose Jen as “a semi-reformed level 4 rock chick who’ll probably respond well to spiritual conversation”). He doesn’t report the deaths he’s played a part in and has a day job as a torturer of sorts. He’s also–and we’ll get back to this–a deeply unreliable narrator. Does all that though, mean that Matt deserves to be ostracised? What’s the future for a society that publicly and permanently shames and excludes anyone found to be a bit of an arsehole? Visibly branded a sexual deviant in festive Santa red to anyone with Z-Eyes, how long do you think it would take for vigilante justice to be dished out to someone like Matt? I give him until the next ad break before that handsome face is spread all over the pavement. Brooker’s drama urges caution here and elsewhere in White Christmas. “Block” someone social media-style in real life and you end the conversation. Any potential for redemption or growth ends with it. These are real people we’re dealing with, they’re not disposable.

“There’s no such thing as real people”

It’s a very neat idea and White Christmas wastes no time in establishing its philosophical quandary (nor, with Rossini’s The Thieving Magpie – now indelibly linked to A Clockwork Orange – and that HAL 9000-style blinking light consciousness-in-a-box, its sci-fi influences). What are our responsibilities to the people who provide our consumer luxury? And is digital enslavement something we should be signing a Change.org petition about anytime soon? As great as Jon Hamm is throughout, Rafe Spall – up until now a glowering presence in the mysterious snowy outpost that provides the episode’s framing narrative – is excellent in the last story as Joe, TV’s most sympathetic stalker and child ‘n’ pensioner killer.

“I just wanted to make some sort of contact”

Imagine being trapped in a glacially slow-moving perpetual loop of self-hatred, regret and loneliness soundtracked only by the tinny optimism of novelty festive pop. Anyone who’s worked in the retail sector in December won’t have to. Years of dreaming up brilliantly obscene punishments for reality TV dunces and self-aggrandising celebrities in his Screen Burn TV column was solid preparation for Charlie Brooker to write White Christmas’ horrific final moments, which neatly pull taut a thread loosely woven throughout the episode. Whether you saw the final twist coming (and you might, with clues scattered all over the preceding segments from his prison cell-like room to the unexplained sound of his cell hatch being slid open during Christmas lunch, and lines like “it’s not an interrogation” or “it’s a job, not a jail”…), it’s a thrilling development that invites you to rewatch right from the beginning (something that will greatly benefit from the DVD release, when we can do it without all those ad breaks). A sense of menace and unpredictability pervaded the episode-long conversation, which was punctuated by Hamm’s character sharpening both literal and metaphorical knives. Black Mirror having taught us to expect trauma, when Matt gestures at his Z-eyes with a fork saying “you can’t even take them out”, you had to wonder if an eyeballectomy was on the cards. What actually happened wasn’t any less horrific. (Speaking of sly nods, more fun arrived for fans with tips of the cap back to previous Black Mirror episodes. The username of one of the online pervs watching Harry in the first story is I_AM_WALDO, in reference to The Waldo Moment, an episode also referenced in the news ticker running underneath the news of story three’s train crash with the line “MP Liam Monroe claims Twitter account hacked”. On the same ticker is the headline “Victoria Skillane appeal bid rejected”, referencing the protagonist of White Bear, also directed by Carl Tibbetts. And was that the talent show from Fifteen Million Merits glimpsed mid channel-flicking?)

“Not much of a Christmas story”

When it was announced, the idea of a Black Mirror festive special seemed like a brilliant joke in itself. (I’m not sure we’ll ever recover from Rory Kinnear and that pig.) What, we asked ourselves delightedly, will Charlie Brooker’s expertly acerbic imagination dream up to stomp Godzilla-like all over the season of goodwill? How – ha ha! – is he going to ruin Christmas? He isn’t, is our answer. White Christmas’ nightmarish tales of isolation might be dark, but they show sage concern about the kind of world we’re building for ourselves. They ask us to consider the humanity of how we treat people online and in the real world. An extreme reflection it might be, but underneath it all, Black Mirror may well have the most charitable heart of any of this year’s seasonal specials.