Accidental Death of an Anarchist has been performed all over the world with varying degrees of success. Written by Dario Fo and his wife Franca Rame, the script was inspired by an actual case of police brutality in 1969 when a train driver with anarchist leanings was found dead beneath the open window of a fourth-floor interrogation room. Official reports described the fatality as ‘accidental’. The plot structure is borrowed from Gogol’s The Government Inspector. A senior civil servant arrives in an isolated town and exposes the corrupt and self-serving ways of the townsfolk. After he departs, the civil servant is exposed as an imposter.

Here, the authority figure is a mercurial exhibitionist, the Maniac, whom we first meet during a police interview. He describes himself as a born diva, a luvvie-from-hell, a non-stop performer who treats all human interactions like an improvised sketch show. His business card, he tells the cops, is a dramatic script which falsely claims that he graduated from Cambridge, but this untruth is permissible to anyone who accepts that business cards are works of fiction. His zany sophistries are faultlessly logical. The Maniac learns that a suspicious death in custody is about to be investigated by a judge so he disguises himself as a leading member of the judiciary and starts to interrogate the police. But because he loves fiction, he encourages them to embellish and falsify their testimony. Which they do with relish. By treating the cover-up as an act of mischief rather than a shameful crime the script maintains its playful atmosphere and never descends into self-righteous homily. It’s a superb feat of writing by Tom Basden who adapted and updated the original text.

Daniel Rigby is a tour de force as the Maniac, gripping the crowd from the very opening moment. ‘Do you believe in the fourth wall?’ he asks the audience. ‘Too late!’ he cries, flinging his coat into the stalls. Rigby has the explosive, feral energy of Adrian Edmondson, which he tempers with a cool, knowing intelligence and a polished external demeanour. He could be a young Roger Allam. The supporting players are just that, assistants and helpers who enable the comic whirlwind to spin and roar. The script requires the Maniac to take on multiple roles as ringmaster, theatrical director and lead character. And he turns into a Greek chorus when he delivers topical asides and footnotes.

By a weird coincidence, this show about police brutality has opened in the capital just as the Met finds itself at risk of being broken up following a series of scandals. Some shocking details penetrate the script: from a list of 1,800 misconduct allegations, only 13 resulted in disciplinary action against officers.

The levels of absurdity increase in the second act as the Maniac drops his judge’s disguise and assumes the persona of a forensics expert from Derby who wears an eye-patch and a false arm. Countless jokes about disability follow and none of them is offensive because they rely on the play’s defining argument that all human life is spurious make-believe. It’s amazing to see a farce that sustains its satirical momentum for two solid hours. That’s a long stretch for a comedy. This show is hilarious throughout. A flawless production. Sheer magic.

Leaving Vietnam is a monologue written and performed by Richard Vergette. He plays ‘Dutch’, a motor mechanic, who quit his job in Detroit in the mid-1960s and joined the marines in search of military glory. But conditions in Vietnam were more brutal and riskier than he’d expected. Deployed to the DMZ, or demilitarised zone, he hears it referred to as the ‘dead-marine zone’.

Back in the US, Dutch discovers that he’s not a war hero but a figure of suspicion and hostility. Draft dodgers who fled abroad are fawned over and invited to deliver lectures about their sufferings in peaceful countries such as Canada. But Dutch has no audience for his tales of real danger in combat. He admits to war crimes, or near war crimes. While interrogating an unforthcoming Vietnamese peasant, he felt tempted to execute the man on the spot but he simply burned his home down instead. This incident was later used in a celebrated anti-war book written by one of his comrades. To Dutch, that feels like yet another betrayal.

He gives the show a topical spin by placing a Maga cap on his head but he removes it after a few moments without exploring the theme of populist right-wing figures and their appeal to disaffected, blue-collar rust-belt citizens like him. A shame. Vergette is perhaps too ashamed or fearful of Trump to consider why the ex-president still enjoys the support of tens of millions of Americans. No one will learn anything from the theatre if writers censor themselves and dodge the big issues.