It’s Christmas! And that can mean only one thing: every second theatre in London is showing their own adaptation of A Christmas Carol. So what if you fancy a festive show but you’re not in the mood for Dickensian drama? Well, I suggest getting yourself down to Leicester Square Theatre, where quite literally anything can happen, and no two performances will ever be the same, as the Shit-Faced Showtime team return with A Pissedmas Carol.

In essence, the show (written by Lewis Ironside, Issy Wroe Wright and James Murfitt, and directed by Katy Baker) is a fairly straight retelling of Dickens’ well-known story, but with a significant twist. Prior to the show, one member of the cast gets well and truly sozzled, and then proceeds to wreak havoc while their sober colleagues attempt to keep the story vaguely on track. This sometimes proves quite tricky, particularly when a throwaway comment from Tiny Tim’s by now decidedly inebriated mother takes the story in a new – and somewhat less feel-good – direction. There’s also a change to Scrooge’s family history, requiring both young and old Scrooge to instantly adopt an Italian accent, and a visit from Mystic Tweg, which results in an unexpected boob job for Scrooge’s niece Emily.

Most of the fun of the show lies in watching the rest of the cast react to whatever the drunk actor says or does, and then carry the jokes through the remainder of the evening. As with all good improv, it’s just as rewarding to watch very talented performers think on their feet as it is to watch a very drunk one try to derail the show. There are also moments (albeit quite few and far between) of relative calm when the troublemaker isn’t on stage, and we get an opportunity to enjoy the acting and vocal talents of the rest of the cast. Because yes, this is also a musical, featuring a number of modern Christmas hits written more or less seamlessly into the plot and performed incredibly well, given the circumstances.

If you’re easily offended, this might not be the show for you; expect very bad language, naughty jokes and – obviously – the celebration of drunkenness (the show has various mechanisms built in to ensure that the drunk actor remains as drunk as possible). But if you’re after something a bit different and very silly this festive period, you could do a lot worse than give Shit-Faced Showtime a try. It’ll be unlike anything you’ve ever seen before, or ever will again, and guaranteed to get you feeling festive. God bless us, every one!

A Pissedmas Carol is at Leicester Square Theatre until 15th January.