Experiencing the terrifying force of an Australian cyclone gave playwright Bryony Lavery the starting point for a show about faith and acts of God.

The Believers – which begins with a flood that throws two very different couples together – is Lavery’s third collaboration with physical theatre company Frantic Assembly – an experience she says has totally changed the way she writes.

“I would love to sound as though I was a seer about this winter’s floods, but this was inspired by taking a show to Australia. I visited a friend in northern Queensland and went through the most extreme weather I have ever experienced – it was as if the wind had claws and was trying to tear off the roof. It did feel as though there was an alien evil presence trying to pull the house apart and get to us.”

The 70-minute piece sees one family take in the other because their house is underwater. One couple believes in God, the other doesn’t, then there is a miracle that cannot be explained.

The 67-year-old, best known for the powerful play Frozen, about a convicted paedophile and the mother of one of his victims, wanted to explore opposing beliefs.

One couple thinks we’re responsible for climate change that leads to dramatic weather, the other that acts of God are payback for being miserable sinners.

‘Faith requires a leap’

“There’s a bit in Mary McCarthy’s Memoirs of a Catholic Girlhood that’s always snagged in my brain – that faith requires a leap, it isn’t explicable, you either believe or you don’t. I don’t think I have a faith, but I find that incredibly interesting. There is always that bit when there isn’t proof. It’s wonderful stuff for drama – there is conflict, hope, desperation and disappointment.”

Lavery’s previous critically acclaimed work with Frantic includes Stockholm, which dealt with domestic violence, and Beautiful Burnout about boxing.

Rehearsals start with a theme and no script, exploring first what can be told physically, before Lavery starts to write.

“They usually come with the broad area – this was belief systems, what we believe and why? They send me anything they have been reading about the subject.

“In this, two couples are tied together by long ropes and we spent a while trying to stick the lightest of the actresses to the wall and move them across it!”

Lavery says working with the company was “a wonderful accident waiting to happen”.

“I had been waiting to find them. The more I have discovered, the more of a complete revelation it has been – it opened my eyes to the possibilities of telling a story as much by sound, light and physical expression as by words – that physical expression doesn’t have to be naturalistic. It’s released my inner choreographer and spilled over into all my other work – well, perhaps not the radio, although I am trying.” Currently adapting Armistead Maupin’s Further Tales of the City for Radio 4, Lavery says gleefully: “I’ve just written in a fight!

She’s also adapted Robert Louis Stephenson’s Treasure Island for The National Theatre’s Christmas family show. “It’s made me think that characters don’t always have to say things to show what they mean. Most of our experiences of strong emotions are silent. We are quite gobstruck and rarely say, ‘I am feeling like this’.

“My aim is to keep it as spare as possible and write as few words to give the sound and acting space.”

At the suggestion that it’s generous of her to pare back her role to serve the project, she quips back: “Generous or lazy.

“I always have plenty of words. I have a lot of wordy plays in my past. One always wants it to be for the greater glory of you but, actually, if a play serves everyone, it’s great because the other parts throw good words into relief.”

The exciting possibilities of marrying narrative, speech and physical theatre in work by Frantic Assembly and Complicite have enriched other text-based drama, says Lavery.

“A huge debt must be paid to the likes of Frantic and Complicite. Their work has permeated and changed the landscape for the better – it’s spreading like wildfire.”

n The Believers is at the Tricycle Theatre, Kilburn High Road, from April 22 to May 24. Box office: 020 7328 1000.