It's 1834, and on the back of three flops, Charles Dickens (Dan Stevens) could really use a bestseller. Desperate, he bangs out A Christmas Carol over six frantic weeks, a book he hopes will keep his growing family above water. Friends and collaborators are not convinced, Christmas being a minor religious holiday at the time. But drawing on real life people, including his roguish father, as played by Jonathan Pryce, and an ailing Tiny Tim-alike nephew the author comes good and invents – or at least codifies – everything we know about Xmas.

Susan Coyne’s smart screenplay sees these real world antecedents rubbing shoulders with composite characters (notably Tara, an Irish maid with a flair for ghost stories) and Dickens getting into loud arguments with his fictional creations.

Oh, the compound ironies: Dan Stevens, the man who ruined Christmas for millions in 2012 (when his Downton Abbey character Matthew Crawley was killed off), is back to restore the festivities. It's almost as paradoxical as the Dickens he portrays, a man of conscience determined to save Christmas from capitalist greed, so that it can become the holiday of, well, capitalist greed that we know and love today.

Stevens makes for a dynamic, restless protagonist, a livewire human riposte to the two things everybody knows about the socially mindful author: that he’s Victorian and long dead. Christopher Plummer enunciates and rolls the stuffing out of every word as he rockets his way to the upper echelons of the Ebenezer Scrooge league table.

Despite these turns amid a rather terrific larger ensemble, and the surefooted direction of Bafta winner Bharat Nalluri (Spooks, Life on Mars), The Man Who Invented Christmas, which was largely shot in Ireland using sets from the now defunct Penny Dreadful, looks and feels like a seasonal TV special. One half expects a retail sponsor flogging luxury mince pies to appear on screen at any moment.