On demand: "A Christmas Carol"

The latest version of A Christmas Carol to reach us is an adaptation of the one-man show Simon Callow has spent the past few years touring repertory theatres the length and breadth of Britain. It's clear from the opening shot - peering out at snow falling from the window of an abandoned office space that speaks to years, if not centuries, of pennypinching - that director Tom Cairns has no intention of opening out the material. Instead, he makes it more intimate, informal: this retelling is a fireside chat, with Callow - in an actor's dream - playing the roles of speaker and listener alike. We've seen this venerable performer wobbling his jowls and chewing his way through so much scenery in recent years that anybody who walks in halfway through and sees Callow capering à la Fezziwig and talking at length to himself could be forgiven for thinking the actor had finally lost it. This, you sense, is the triply spooky Christmas Carol that Callow would have performed had those rep theatres been completely empty, and had the show's failure ruined him professionally, financially, mentally; David Raedeker's camera glides around this Scrooge like another of the tale's spectres. Yet it is a ghost story, you remember - the tale of a solitary man being pushed to the brink of derangement and thus some breakthrough - and there is real, compos mentis thespian skill to be observed in the subtle shifts of body and voice by which Callow comes to differentiate between our genial, slightly gossipy narrator and a set of characters who represent a spectrum of approaches to the material world.

In the past, filmmakers have been drawn to this story for the spectacular possibilities it hands them like a shiny new sixpence, be those chuckling Muppet ghosts or a swooping CG Jim Carrey. By contrast, the effects Cairns reaches for are tangible, plastic, theatrical: a window opening itself over Callow's shoulder, a clock winding onwards to mark the start of Scrooge's long dark night of the soul. Yet clever cutting shifts us - as it shifts the protagonist - from one room, one vision to the next in a disconcerting, dreamlike way it would be hard to achieve on stage, and Cairns loads his soundtrack with connoisseurial glee, alert to how much noise Dickens' prose set ringing between our ears: the doorknocking and chainrattling, the ticking clocks and tolling bells. It presents as very much a Christmas Carol for austerity Britain: though it bears the BBC Films logo (emerging on BBC4 last weekend after a one-night engagement in cinemas earlier this month), you half-expect to see old Ebenezer himself listed among the producers, given that Cairns and Callow have really been given no more than a set of mismatched furniture and a couple of changes of lightbulbs to make merry with. Yet it knows it's working from a great story - one profoundly wise to the deathliness inherent in conservatism, and the gains to be made from embracing change - and that it's been handed to an eminently gifted raconteur. Sometimes that's all you need to warm your heart on a cold midwinter's night.

A Christmas Carol is available to stream via the BBC iPlayer.