ext year promises the arrival of a fifth series of the long-running Scottish sitcom Two Doors Down (BBC Two), but here for now is a typically self-contained festive special, which so closely replicates a certain type of family Christmas that it almost makes up for not being able to gather in large numbers. The action has moved from the front room of Latimer Crescent to Cathy and Eric’s holiday home in the Highlands, lit up more like a city centre’s main shopping street than a Christmas tree. Cathy, never knowingly understated, has invited her neighbours for a post-Christmas break in the great outdoors. This is a comedy very much fixed on the great indoors, however. In the tradition of The Royle Family – which Two Doors Down has in its DNA – the characters barely move from one room to the porch. Eric is excited to experience what Colin calls “the true Scotland: the hills, the glens, the lochs” and Eric and Beth plan to get out for as many walks as possible. “All right, Eric, we’re not on fuckin’ Springwatch,” says Cathy, who is desperate for everyone to stay in with her and sink as many festive drinks as possible. Arguing about whether or not to go for a walk is as traditional as mince pies, but this is such a good, dependable ensemble cast that it is easy to settle in for 10 minutes of bickering about it. Doon Mackichan is delicious as the permasozzled, semi-monstrous Cathy, dictating which toilet her guests can use to “do all your sit-downs”, intensely flirting with Ian’s boyfriend, Gordon, loudly rejecting terrible gifts and, worst of all, ruining long-suffering Colin’s Christmas Day. When sweet, jumper-loving Gordon does a well-meaning impression of his host, her love for him curdles; she retaliates with excruciating viciousness, taking it way too far. It is uncomfortable, mean and very funny indeed. It is also a delicate balancing act. A harmless discussion about the best Christmas telly, complete with bad impersonations – though, really, is that ever a harmless discussion? – turns sour because Cathy is a mean drunk who wants to keep drinking and drinking. But even if it makes you feel bad about finding it funny, Mackichan is incredibly, irresistibly funny. Elaine C Smith is similarly great as Christine: blunt, dour and entirely unwilling to adjust her behaviour in company. She spent Christmas alone, without Christmas dinner, supposedly in solidarity with those who had no one to celebrate with, although in truth, she says: “I’m still making my way through all the pasta I had delivered in March.” That and a KFC family bucket. She reminisces fondly about a blanket covered in salad cream. When Ian and Gordon announce their engagement, she wonders how the wedding ceremony will look in, well, decidedly unflattering terms. There is something oddly comforting in comedy that exists within a locked-down or restricted world. It has seemed increasingly jarring to watch series that go on as if nothing has changed. It is welcome, sometimes, of course – I don’t always want to think about masks and hand sanitiser and that period of time in which we washed our weekly shop before putting it in the cupboard. But this weaves the pandemic into its observations with ease and is much better for it, whether that is Cathy hugging everyone she wants to hug, but firmly sticking to the regulations for those she does not, or all the references to panic-buying and a new love of baking. Although Two Doors Down sometimes gets compared to Gavin & Stacey, it isn’t as silly or as warm. Instead, it depends on the idea that we all know people who are vaguely like this, if not exactly like this. It has its moments of reconciliation, although it reaches them through gritted teeth, as if straining to get there. Arabella Weir continues to hold the toughest job as nice, normal Beth, but she is a necessary foil. The humour is wry and abrasive and it knows how to hold a punchline way beyond the point of comfort. If Smith doesn’t win awards for her impression of Val Doonican, long and brilliantly absurd, then it will be a grave injustice. The staginess of Two Doors Down makes it feel intimate, even in a living room as vast and high as this one. It is familial and familiar and, for those of us missing family gatherings this year, this is an accurate re-enactment of some of its most awkward corners. Eventually, the friends reach a festive truce. After all, what more is there to Christmas than putting the telly on and having a meringue?