JOHNNY McKnight wasn’t aware of Deathtrap when he was asked to direct it at Dundee Rep. Given the writer, director and co-founder of Random Accomplice Theatre Company’s pop cultural roots, this was a surprise to him as much as anyone else.

“I’d never heard of it,” he says of American writer Ira Levin’s Tony-nominated play, which still holds the record as the longest running comedy-thriller on Broadway. Four years later it was adapted for a film starring Michael Caine and Christopher Reeve and directed by Sidney Lumet.

“One of my favourite films is Charade, which is both a comedy and a thriller, and that’s what I liked about Deathtrap. There’s loads of twists and turns, there’s a touch of humour, and it’s loaded with really sharp dialogue.

“It also felt really modern. I was surprised it was from the late 70s, because it looks more like a post-modern take on Dial M for Murder or something like that. It feels as well that somebody who knows that genre really well and gave it a wee twist so it still felt fresh as well as knowing.”

Deathtrap is a play within a play that charts the travails of a successful playwright suffering from writers’ block. Having read one of his students' plays, the writer suggests to his wife that he could murder his protégé and claim his work as his own. What happens next is a series of double bluffs that keeps the audience on its toes as thrill is piled upon thrill to keep the audience guessing right to its darkly comic end.

Beyond its initial Broadway run and the subsequent film, Levin’s play has become something of a staple of the commercial touring circuit. In 2002, a production featured David Soul and Susan Penhaligon in the lead roles, while in 2017 Paul Bradley and ex EastEnder Jessie Wallace toured in the play.

While many of his works ended up as films, Ira Levin was best known as a novelist, with Rosemary’s Baby, The Stepford Wives and The Boys from Brazil all ending up on the big screen, as well as later novels such as Sliver. It was in his plays, however, where his forensic understanding of genre seemed to have most fun, often lampooning some of the vanities of his own industry.

Levin’s 1960 play, Critic’s Choice, is a comedy that focuses on a theatre critic whose wife writes a terrible Broadway play which the critic wrestles over whether to review it honestly or not. The play was later made into a film starring Bob Hope and Lucille Ball. Another play, Footsteps, features a best-selling novelist who is visited by an obsessive fan who knows everything about her. It too was made into a film, albeit for TV only, starring Candice Bergen.

“The big thing that Ira Levin was sending up in Deathtrap was the pretence of people wanting to be rich and famous without doing anything,” says McKnight. “It’s like that even more now with reality TV, where people would rather be known for just being famous rather than for their craft and being good at what they do. Ira Levin takes all that, and understands the genre perfectly, but writes it with a dark humour that runs through it like a stick of rock. I know this will sound stupid, but it’s like panto. You respect what’s gone before in the genre, and then you try and give it a fresh twist. In that way I felt I understood what he was trying to get at with the play.”

McKnight is diplomatically wary of the film version. “It’s very 80s,” he says. “It’s not like the play. Ira Levin wasn’t involved in the film, so the dialogue’s not as good, and it feels very schlocky. I watched it, and I thought, well, I can forget about it now.”

The evergreen appeal of thrillers, murder mysteries and other brands of pulp fiction designed to keep you guessing, be it on page, stage or screen, is something Levin clearly understood in Deathtrap. The recent wave of Agatha Christie revivals and similarly inclined works by a new wave of writers tap in to a similar sensibility. The likes of Dial M for Murder, originally written by Frederick Knott for television before making it to the stage and made famous by Alfred Hitchcock’s film do likewise. While many of these have become touring favourites in a similar way to Deathtrap, many have been reassessed beyond their surface hamminess.

McKnight is full of praise for writer Sarah Phelps’ dark re-workings of Agatha Christie in TV productions of And Then There Were None, The Witness for the Prosecution and the forthcoming three-part adaptation of Ordeal by Innocence.

“She has a proper feel for them,” says McKnight. “They can sometimes be played as camp, but she really gets into the body of the stories.”

Beyond Deathtrap’s subversion of form, there are also hints of a gay under-current running throughout.

“It’s the whole point of Act Two,” says McKnight. “It’s not subtext. That’s the reality of what’s going on, and you can’t take it out, because that would remove any emotional stake, and it’s there for a reason. Compared to the stuff that’s seen on a stage these days, it couldn’t be more subtle.”

However much Deathtrap upends its roots, the appeal of thrillers is a no-brainer.

“I think everyone’s fascinated with thrillers because we all wonder what it will take to kill someone,” he says. “It’s the same reason why some people become fascinated with serial killers. It’s always interesting to find out how bad a person can be. That’s partly why we go to the theatre to watch plays like Deathtrap, to watch these things happen onstage, and then feel glad because we’re sane.

“It’s like when you have a row with someone, and when you tell someone about it, the phrase ‘I could’ve killed them’ is never far away. Everybody’s had that feeling, but most of us never do anything about it, whereas in thrillers and murder mysteries, you can be taken into the darkest corners of other people’s minds.

“Doing a show like Deathtrap in February as well feels right. Christmas has long gone, and your Visa bills have come in, so no wonder you’re having dark thoughts.”

McKnight isn’t over-intellectualising the play, however, and won’t be imposing any kind of ill-fitting concept on a work that’s perfectly capable of standing on its own two feet.

“It does what it’s designed to do,” he says, “which is to bring out an audience who know that genre, and think they know the formula, but which then plays with that. I think Deathtrap has a sense of playfulness which a lot of things from that genre probably don’t. Dial M and all that can be seen as being quite dusty, and they feel like they’re stuck among a certain class of people who are all really uptight. Deathtrap is the reverse of that. You think you know what you’re going to see, but it’s not about uptight people, and the worst thing you can do with a play like this is to try and camp it up.”

McKnight checks himself for a second.

“Listen to me,” he says. “When have you ever heard me talking about trying not to be camp?”

Deathtrap, Dundee Rep, February 10-March 10.