Watching The Lieutenant of Inishmore you get the feeling that everyone on stage is having a good time. That might just be down to the darkly comic script as penned by Martin McDonough in 1993 while the Troubles in Ireland were in full flow, or the vigour they seem to throw behind their lines. But regardless, this is a comedy that caused outrage in 2001 when it was finally first staged, and astounds now with the cut and thrust of its lasting humour.

The tale of a crazed republican Padraic ­– played by the mop-haired Aidan Turner – whose only weakness is a love for his cat, Wee Thomas, is absurd and farcical. Returning to find Wee Thomas dead, wild, Padraic doesn’t hesitate in pulling his gun on his own father Donny – a strong, support Denis Conway – and local lad Davey – played by Chris Walley in an unexpectedly strong performance from this newcomer. Twisted and a little weird, it’s just what you would expect from the writer who went on to pen this year’s Oscar-hit Three Billboards Outside Ebbing, Missouri.

Aidan Turner is the obvious draw here, drawing potentially some unsuspecting audience members to McDonagh’s gloriously gore-y piece. But one imagines Poldark crowds will be delighted and shocked in equal measure in Turner’s ‘Mad Padraic’. There’s the rippling arms, the beautiful lilting voice, but more unhinged hysteria and feline fetish.

He has the energy for this terrorist who’s too mad for the IRA, and obsesses over creating a splinter group from the INLA. Yet Turner also manages to make his emotional outbursts when he hears that his “only best friend in 15 years” the cat Wee Thomas is “poorly” believable rather than over the top, cringey ham. He’s a tender terrorist in his love for his animal over anything else, and Turner lets this bleed through into the torture scenes so that you feel something more for this madman, more than you think you should.

And while it may seem like a given that Turner, who still has women swooning over his Cornish farming techniques and has starred in Peter Jackson’s The Hobbit, is going to be good. But actually, it’s worth remembering that this is his first theatre role in ten years, and perhaps more notably, his West End debut. This is a bold move from the steadily rising star, and it’s paid off handsomely.

He is well matched by Charlie Murphy who plays Davey’s sister Mairead. A wild-eyed budding Padraic-apprentice, who is often mistaken for “a boy in lipstick”, Murphy plays Mairead as strong-willed, haughty, and committed to the cause. Murphy is a true rival to Turner’s lead.

The Lieutenant of Inishmore may be over 20 years old but it doesn’t fail in stoking the soul. Much like Jez Butterworth’s The Ferryman, which dominated London’s theatre scene last year, this play shows that the tales of the Irish Troubles are still pertinent. Igniting laughter, pity, and shock, McDonagh’s script is a masterpiece, and feels like its own its way to becoming a modern classic.

The Lieutenant of Inishmore is playing Noel Coward’s Theatre until 8 September

Photo: Johan Persson