His magnetic performaces in Happy Valley and War&Peace have made James Norton a household name, not to mention a heartthrob.

But does his screen presence transfer as powerfully to the stage? The answer, apparently, is yes.

In this 130-seat, pop-up theatre space on Charing Cross Road, Norton and co-star Kate Fleetwood couldn’t be more exposed.

Not only do they frequently strip to their underwear, the audience, seated around this claustrophobic seedy motel room, are virtually within touching distance, as they play two lost souls so convinced that they are infested to the core with bugs that they eventually spiral into insanity.

This revival of Tracy Letts’s 1996 play touches at times upon every meaning of the word ‘bug’. When awkward, slightly odd Peter (Norton) turns up in lonely, troubled Agnes’s Oklahoma motel room, he appears to bring with him an infestation of aphids.

Peter, who claims to have been in Syria, admits he’s ‘in trouble with the army’ and seems paranoid about surveillance, insisting on drawn curtains, locked doors and – ultimately – tinfoil on the walls to stop ‘transmissions’.

The mites appear to crawl under their skin when Peter is most stressed – when he’s bugged, basically. And as lightbulbs flicker above us and a buzzing sound grows more present, the audience become agitated – bugged even – in what is an intense and unsettling night out. As cocaine snorting tragic Agnes, the cat-eyed Fleetwood is utterly compelling, while Daisy Lewis as her friend, and Alec Newman as her abusive ex, provide strong support.

An edgy, vulnerable Norton in his pants will inevitably be a draw for some theatre-goers, but when he takes a pair of bloody pliers to wrench out a tooth he insists has been bugged, I suspect even his biggest fans will avert their eyes in horror.

Bug at Found Theatre 111.

Rating: 4/5 stars.