There’s nothing quite like It’s a Wonderful Life. The beloved 1946 Christmas film in which James Stewart plays a despairing man who’s shown what the world would look like if he’d never been born, is, to many of us, as treasured and essential a part of the festive period as Santa Claus himself.

Yet like so many of the best Christmas stories – including this film’s key antecedent – Charles Dickens’s A Christmas Carol – It’s a Wonderful Life is more than just mistletoe and good cheer. In fact, it’s made richer and more moving by its inherent darkness. Its reputation among sceptics for being rose-tinted schmaltz belies the fact that this a film about a man pushed to the brink of suicide. And set against a background of war, collapsing financial markets, families struggling to get by and mental anguish, perhaps the themes are still as relevant, if not more so, today.

Nelson’s adaption is both faithful and inventive. Written for just four actors – though it can be played with more – the play is fluid with quick and flowing transitions from Heaven to the key buildings within the small town of Bedford Falls. It’s also pacier than the original and includes audience interaction, yet it still remains truthful to the original narrative, ensuring that Capra’s message about valuing what we have shines through.

This is a fable about a man unhappy with his lot in life, struggling with fears of inadequacy, unaware of his own social impact. The film itself was regarded as a failure – only to be later embraced by the world (after years of seasonal TV airings) as a bastion of profound joy and comfort. What would the world look like if It’s a Wonderful Life had never been made? I don’t think any of us would want to find out.