People Show is Britain’s longest surviving alternative theatre company, debuting in 1966, and the joy of their 121st outing is its unabashed, old-fashioned entertainment.

PEOPLE SHOW 121: THE DETECTIVE SHOW Old Red Lion 70 mins ***

People Show is Britain’s longest surviving alternative theatre company, debuting in 1966, and the joy of their 121st outing is its unabashed, old-fashioned entertainment.

This zany lampooning of the whodunit takes pot shots at everything from Agatha Christie and Taggart to Prime Suspect and even Cluedo, and if some gags miss the mark, there are still more than enough in this packed 70-minute sketch show to satisfy.

The comic layering offers two options: if you tire of the music hall farce, with its mime, slapstick and daft disguises, there’s also a barbed post-modern thread, as Gareth Brierley’s unctuous narrator breaks the fourth wall to reveal backstage tensions and deconstruct theatrical conventions.

If you ever wondered about the gulf between programme notes and the actual content of a play, he has the answer.

There’s stellar support from founding member Mark Long, who gifts us a waiter more stereotypically Italian than Bruno Tonioli, and Fiona Creese, strong as both the voice of reason and an idiosyncratic take on Poirot, while director Jessica Worrall keeps the unwieldy train on the tracks.

However, the company’s combination of devised physical work and meta humour isn’t as radical as it once was, with mainstream hits like One Man, Two Guvnors and The 39 Steps in the West End and Charlie Brooker’s sharp pastiche A Touch of Cloth.

Where People Show suffers by comparison is lack of specificity and the indecision as to whether these storytelling tropes are useful in engaging an audience or mere objects of ridicule.

Still, where else can you see a Monty Python-esque seagull salad, plot twist involving Hitler’s condom and a perfect 10-second skewering of Bob Dylan?

This is a great reminder that theatre can be inventive, inclusive and above all fun.

Until November 2.