The West End is embracing violence. While at The Trafalgar Studios Orlando Bloom stars as a menacing cop in Killer Joe, in which a father and son plot the murder of a son’s mother, here Aidan Turner takes on the title role in a blood fest that is about as far from Poldark as you can imagine.

In this darkest of black comedies first seen in 2001 though written in 1994 by Three Billboards Outside Ebbing, Missouri creator Martin McDonagh, Turner is “mad” Padraic, a self-styled lieutenant of Irish republicanism, a loose-cannon who is too violent even for the island’s terrorist community.

The play opens in rural western Ireland, where it is mostly set, with Padraic’s dad Donny (Denis Conway) and hapless local lad Davey (Chris Walley) contemplating a dead cat which Davey discovered while out riding his bike. Donny recognises the poor moggy as Wee Thomas, his son Padraic’s beloved cat, whose care the terrorist entrusted to his father while he went off killing and bombing his way through Ulster. Someone is going to pay for Wee Thomas’s demise and top of the list is his dad, who he might not hesitate to murder, while second is surely Davey whether he deserves it or not.

It’s not a play for the squeamish. And whether it’s cutting up bodies, or shooting people in the head, Michael Grandage’s production doesn’t hold back o from explicit detail. Yet the comedy and irony flows from McDonagh’s pen runs so fast, you’re as likely to be laughing at what you hear as you are appalled by what you see.

In his West End debut, Turner, who in Poldark is the owner of the most lusted-after torso on television, is a revelation as the emotionally stunted Padraic. Granted, his moral compass doesn’t exactly point north, but there is a vulnerability to the man. Even as metes out the most terrifying violence, he breaks down in tears at the thought of Wee Thomas feeling a little peaky. And throughout this play murder and mayhem are spoken of and enacted as casually as a butcher bones a chicken.

This is McDonagh’s point. Violence is the target of his play, as well as the cause in whose name it is carried out which becomes justification for almost any barbaric act.

Turner is superbly supported here by a cast that revels in the Father Ted-ness of some of the comedy. Walley and Conway in particular mine this seam as Davey and Donny desperately attempt to hide Wee Thomas’s demise by finding a stand-in, a ginger cat whose colouring they not-so-cunningly disguise by covering it in shoe polish.

There will be those who reject the offensive Irish stereotype. And there will be those like me who both reject it and laugh at it too.

My first impression from 2001 remains unchanged — this is a brave criticism of the way violence becomes, not just the means to an end, but the end itself. But also that in the way he characterises some of Irish who live in that world, McDonagh has kind of got away with murder.