We should all be prescribed an Ali Smith a week these days. After finishing a novel of hers you are left more able to live in a world that can be better appreciated as both terrible, with all its suffering and hypocrisy, and wonderful, with all its art and love.

Charles Dickens is quoted in an epigraph, “Darkness is cheap”. Like A Christmas Carol, Winter, the second of Smith’s seasonal tetralogy, is about the possibility of redemption. Sophia is lonely, estranged from her family, a Scrooge-like character who (and Smith lightly toys with the allusion) is “being haunted (if there were such a thing as being haunted, rather than just neurosis or psychosis)”, by the head of a child. Her son Art, a nature blogger who describes himself as “just not a politico”, has been left by his girlfriend who is exasperated by his apathy, and he has to find a stand-in partner for the Christmas visit to his mother’s. Lux, the stand-in, and Iris, Sophia’s estranged sister, help restore these characters to life. In the context of a planet threatened by reactionary politics, ecological disaster, and the threat of nuclear war, the story remains hopeful.

Characters learning to be more open and welcoming must be read partly as political allegory in the light of the Theresa May epigraph: “if you believe you’re a citizen of the world, you’re a citizen of nowhere”. The feeling of watching news unfold is described as “like walking in a blizzard all the time just trying to get to what’s really happening beyond the noise and hype”. A text from Iris to Art explains Smith’s philosophy: “the diff dear Neph is more betwn artist and politician – endlss enemies coz they both knw THE HUMAN will always srface in art no mttr its politics, & THE HUMAN wll hv t be absent or repressed in mst politics no mtter its art”.

And to describe the book only in terms of its politics is to miss the enthusiasm for humanity that makes it so enjoyable. Smith skips lightly across decades to tell a love story, and slips between third person narration and internal monologue to allow intimacy with all characters. Her enthusiasm for art is infectious. Lux tells the story of Shakespeare’s Cymbeline, in which “the people in the play are living in the same world but separately from each other”. Sophia considers how Elvis Presley, singing Wooden Heart in a puppet show in the film G.I. Blues, “throws a look so small it’s nearly not there to the girl he loves in the audience”.

An hour, once the book is finished, should be set aside for flicking through the Riverside Shakespeare, YouTubing clips of Charlie Chaplin’s The Great Dictator, and googling the artist Barbara Hepworth. One of the great pleasures of all Smith’s novels is that you are dispatched on such cultural treasure hunts, and Winter is no exception.