If you really want to know what it’s like to feel trapped, not to say incarcerated, in a theatre, go see Liberty by Glyn Maxwell. It’s a punishing, mostly incomprehensible verse play about a group of revolutionaries during the Reign of Terror, based on a 1912 novel by Anatole France called Les Dieux sont Soif - and most of us felt sympathetically parched by the interval.

It manages to make one of the most exciting and dangerous periods in European history sound like a tea party in Theydon Bois. Which is more or less how the play begins: at a picnic in the countryside outside Paris in 1793, a few months after the execution of Louis XVI. Robespierre is in charge of a committee of public safety and Marie Antoinette is in prison.

Unfortunately, the struggling artist Evariste Gamelin (David Sturzaker) is not locked up with her, but free to bore us rigid with his take-away idealism and half-baked oratory. Gamelin becomes a repressive magistrate and supporter of state violence, though it’s hard to follow, and then swallow, how this comes about and why we should care that it does.

His girlfriend Elodie Blaise (Ellie Piercy), shy enough to be re-christened “Modesty” perhaps – is a humble seamstress continuously upstaged by an overbearing actress, Rose Clebert (Belinda Lang), who’s a butt for a stream of humour-free references to the National Theatre.

By the second act, Evariste is apparently closing down the newspapers and the theatres while an eccentric old duke, Maurice Brotteaux (John Bett), takes to puppetry with about as much success as I would take to unicycling on a trapeze with a fire-eating dwarf on my head. Why director Guy Retallack hasn’t cut this farrago by ninety minutes and given us a salon-style comedy of visionary revolutionaries – “The Importance of Seeing Unrest”? – is a mystery as impenetrable as most of the dialogue.

Actually, Maxwell’s not so mighty sickle and hammer are wielded in limp and turgid verse, or so it would appear from a glance at the script. There is no discernible metre, nor any fizz, bounce or beat to the relentless triviality of the dull lines. There’s a couple of chorus numbers and rumbling tumbrel en route to the guillotine, but nothing that doesn’t make you yearn for a revival of Danton’s Death or a return visit to Les Miserables.

- Michael Coveney