The Unfriend at Chichester Festival Theatre – review

Brace yourselves – Elsa Jean Krakowski is in town and she's not a woman to be messed with!

Steven Moffat – chiefly known for screen writing, most notably for Dr Who – has skilfully crafted one of the funniest plays to be seen on stage in a very long time. In the comedic hands of director Mark Gatiss and a brilliant cast of perfectly timed and genuinely funny performers, this is pure comedy gold. Originally due to play the Minerva in 2020 it was yet another victim of the pandemic – it has been well worth the wait.

Peter (Reece Shearsmith) is taking a relaxing holiday with his glamorously wholesome wife, Debbie (Amanda Abbington). Onboard their cruise ship they meet the bawdy and eccentric Elsa (Frances Barber) on her travels from Denver, Colorado. She's a widow and quickly befriends the married couple – a quick leap in time and a very clever scene change later (bravo to designer Robert Jones) and Elsa is arriving on the doorstep for a friendly visit to her newfound British friends in the leafy suburbs of Chiswick.

With the discovery of a body count in Elsa's past that stacks up even higher than that of the luggage she has brought with her, she is soon under the microscope and inducing fear into Peter and Debbie. Moffat's brilliant stroke here is in the painful display of English politeness that never once allows the couple to confront their unwanted house guest. To their bewilderment, the murderous Elsa manages to turn miracle worker and nanny all in one by energising their slumping teenage son and by injecting positivity into their serially offended teenage daughter – "she's like a Killer Poppins" screams Amanda Abbington's usually poised but steadily unravelling Debbie.

Moffat and Gatiss have created a comedy of manners that niftily speeds along and is full of outrageous humour but always stays just the right side of farce. Perhaps a little too much time is spent on a toilet gag in the second act but otherwise, this is never anything except laugh-out-loud funny. The intimate setting of Chichester's Minerva theatre is perfect for writing that is often more akin to the close-up of TV sitcom than the larger than life stage – actors that understand this level of nuance in the comedy are essential to make it all come together – they do that in spades.

Frances Barber is clearly relishing her role as Elsa – as grotesque as she is glamorous and as deadly as she is motherly, she's a proud Donald Trump voter – "he only lost because of fraud and people voting against him" – and has a brutal honesty about her that leaves the very British Peter and Debbie conflicted in all manner of ways – "she's the killer who came to stay and is every day improving our lives". There is typical Barber bravura in her deliciously over the top Elsa.

Reece Shearsmith as Peter is buttoned up as high as his blood pressure and angry with just about everything in the world. Shearsmith's delivery is exquisite with every move exuding neuroses and bafflement. The perfect synchronicity with which he and Abbington work is joyous and make this a real tour de force of comic delivery together. There is great work also from Gabriel Howell as son Alex and Maddie Holliday as daughter Rosie. Michael Simkins provides an effortlessly tedious neighbour who brilliantly steals the last laugh.

It's a killer comedy to die for.