Moomins do not like winter. In one of Tove Jansson’s stories, Moomin’s Winter Follies, young Moomintroll bumps his head when the sea ‘goes hard’, prompting Moominmamma and Moominpappa to hurry the family into hibernation. They attempt to follow the tradition of their ancestors by scoffing pine needles and covering the furniture in dust sheets before bedding down on hay, but Moominpappa, for one, is troubled by the prickliness of all this: ‘Who said I must do like my ancestors?’ They briefly abandon the idea and postpone their sleep to try some winter sports, but Moomins are not really built for skiing.

In Moominland Midwinter, which premières on Radio 4 on Christmas Day, the family have finally managed to doze off for the season when a moonbeam strikes Moomintroll right in his doughy white face. ‘And now something happens that has never happened before,’ narrates Samantha Bond, breaking from a whisper into a warning tone. The young Moomin wakes and cannot go back to sleep.

This is naturally very frightening. Mooninmamma will not wake up. The clocks have stopped. There is nothing around to eat except loganberry syrup and half a packet of biscuits and who wants those? Nibbling the paltry provisions beneath the kitchen table, Moomintroll does his best to reassure himself — ‘Spring soon!’ — but then he notices two small eyes peering out at him from underneath the sink.

If you’ve seen Moominvalley, the newest animated TV series based on Tove Jansson’s characters, you’ll know that Moomins can sound decidedly modern these days. Taron Egerton, wonderful as Elton John in Rocketman, lends the series’ Moomintroll the voice of a nice defiant bloke living closer to St Helens than Helsinki. John Finnemore, in the radio play, restores the creature’s innocence in the smallness of his sound. His Moomintroll is anxious, especially when out in the snow, where he encounters the shaman-like Too-Ticky (Rakie Ayola), who serves him fish soup and philosophises about death — the last thing a lost Moomin could possibly want to think about.

The story translates well to radio, where it’s well cast, but there is something very special about the illustrations, which the script can do only so much to compensate for. The scene that works best visually features Moomintroll coming face-to-face with one of his ancestor species. The ‘little grey thing’, being ‘very grey and very snouty’, is dismissed by Moomin unceremoniously as ‘only an odd sort of rat’. It is, he is corrected, a troll, and much how he would have looked a millennium ago. Moomin, excellently, ‘has nothing to say about this, so he goes home’. After the travails of winter outdoors it is not a moment too soon. The real adventures begin there.

After hibernating in the previous Christmas special, Roger Allam and Joanna Lumley are preparing themselves for a house full of guests in Conversations from a Long Marriage at Christmas againthis year. Sally and Peter, a couple with a rocky marital history, have invited them to stay in Sussex with some other friends, among them a ‘bespoke loaf of bitcoin bore’ called Simon. To their frustration, however, the plan keeps changing, as plans do, and it’s not long before they’re looking forward to another kind of Christmas altogether.

Written for Lumley and Allam by Jan Etherington, the two-hander is witty and warm and, though not the most original of stories, very good on the fractured rhythms of family life at this time of year. Elements of A Christmas Carol and the Nativity are sewn together with music from the Pogues and Blur, which is less edgy and forced than it sounds. I particularly enjoyed the scene in which the pair weave their way in and out of ‘Gucci tractors’ to go Christmas shopping.

Allam and Lumley have superb timing and chemistry and are consistently entertaining. What lets the episode down is the rather too exacting balance struck between light and shade — the prospect of new life and charity countering loss and loneliness in the context of the pandemic. We expect a bit of schmaltz at Christmas but as a whole it felt slightly too measured. The parts were better than the sum.

I may well be too young to appreciate the dynamics of a middle-aged relationship — the dialogue is likely to go down best with the boomer generation — but I cringed with laughter at the couple’s discussion of ‘orgasmic’ roast potatoes, prepared with ‘hot goose fat and regular tossing’, while wondering what sort of a man turns down sex in favour of going to buy a Christmas tree.