Philip Ridley and I arrive at Southwark Playhouse at exactly the same time. Synchronicity, I like it. Possibly the most amiable, down-to-earth playwright ever, Ridley is the man behind Moonfleece and The Pitchfork Disney. Director of numerous films and songwriter for the likes of PJ Harvey, the man is also much more than a playwright. He uses a multitude of artistic expression from charcoal drawings to performance art, but he’s here to talk to me about his newest work, Tender Napalm. His, shall we say, fiery new play explores the sweet but destructive relationship between a man and a woman.

After much ranting about interval drinks (“I despise intervals. People can’t sit down for two hours!?”) and why theatre critics shouldn’t try to psychoanalyse, (“do they think they’re moral arbiters!?”) he attempts to summarise the play. Understandably, he hates doing this. “If I could say it three sentences, I wouldn’t have spent the last year working on ninety pages,” he laughs. But he obliges. Essentially, Tender Napalm is a couple arguing. Sometimes they argue frankly, sometimes their words are wrapped up in allegory and metaphor but they are trying to work things out – it’s evidence of Ridley’s optimism.

But he’s also quite a realist.“None of the relationships we have over the course of our lives are just about that relationship,” he says; “they’re always about where we are at that stage in our life, and how the world is at that stage in our lives. We don’t always realise at the time. It’s only when we look back that we realise why things happened the way they did.”

I’ve been sent the script. A few pages in and someone’s already reached orgasm, amid talk of tsunami, earthquake and radiation. “The language of the world,” Ridley says, “what’s in the news, it’s filtered into the play, much more pertinently that I could have imagined.” Written in 2010, this isn’t about the most recent tsunami in Japan, nor the Boxing Day Tsunami of 2004; “I was thinking of something that can completely devastate a landscape,” he explains, in the way things can completely devastate a relationship.

The language in Tender Napalm is indeed devastating. “The language we choose to use for love, particularly sexual or romantic love, has become fossilised,” Ridley explains. “We no longer realise how bizarre that language is. One of the things the play is exploring is a kind of reinvention of that language. It takes those words and scrubs them and refreshes them so that at last they starts to mean something again. We hear things like, ‘if you leave me, my heart will break,’ when you could just as easily say, ‘if you leave me, my spleen will be crushed. ” But we don’t say that. ‘Heart will break’ no longer resonates as violent. We don’t imagine a heart rendered asunder. Why can’t ‘I could push a bullet between your lips’ be just as romantic? In the modern zeitgeist, it could well be”

The refreshing of language is not a completely new thing for Ridley. In Mercury Fur, a play about a gang of drug dealers, Ridley reinvents drug taking and it suddenly involves delicate butterflies. “Everyone’s so anaesthetised to seeing drugs in film and on stage – the currency of seeing somebody shooting up or taking drugs has lost its impact. So what I had to do was invent a completely new drug, so when you describe taking this new drug it surprised people. These guys weren’t just snorting coke.”

As complex as the script might be, Ridley’s set is non-existent.“It’s going to be almost the antithesis of what’s become the style du jour in theatre,” he says. “I wanted to do something that is stripped down to its barest essence. You’re going to see two people on stage. No set, no music, no props; just two people on stage giving you the story.” A new, innovative play with no unnecessary multi-media projections. Finally.