When Greg Hopkinson walked into one of the most violent prisons in Mexico - a jail where 44 inmates died in a battle between rival drug cartels - the experience was mind-blowing.
"It was just unbelievable - the peace, contentment, and stillness in the place was palpable.
"Effectively we walked into this massive meditation retreat."
What changed? How did Apodaca prison in Monterrey, Mexico, go from the scene of a violent uprising in 2012 when members of the Zetas drug gang slaughtered rival Gulf cartel inmates to a place of peace and stillness?
It was through a practice known as Ascension meditation.
Today, a quarter of the 2000 prisoners, guards and management in the overcrowded prison regularly practise meditation - and it has transformed life in the prison. Suicides are down 40 per cent; there have been no reports of violence since 2012; solitary confinements are down 50 per cent.
The change is captured in a new film out this month, Choice, which is made by Greg Hopkinson and Sally Lewis, a New Zealand couple who traded life in the fast lane to become meditation-teaching monks.
Choice focuses on how meditation has changed the life of individuals and communities, with the evolution inside Apodaca prison one of the central pillars.
"Three years prior to us being there they had one of the most violent episodes in Mexico's prison history where 44 people died," Hopkinson says. "The change there is just unbelievable."
The couple saw first-hand how meditation had changed the lives of not only the prisoners and staff but also their families outside the prison. As one woman says in the film, it's like dropping a pebble in a pool of water and seeing the ripples move out.
"What the guards and prisoners wanted most was a change for their families and children," Lewis explains. "And they soon saw by choosing peace for themselves they began to see the effect on their families and wider community."
Teaching meditation in prisons is not new.
One of the leading advocates for the practice is cult film-maker David Lynch who advocates for transcendental meditation in prisons through his David Lynch Foundation, which states meditation can reduce recidivism rates by 30 per cent, as well as decreasing criminal thinking, depression, fatigue and anger.
Hopkinson and Lewis believe it's something that can, and should, happen here and their Brightpath group is hoping to bring the practice into New Zealand prisons.
"That's the exciting thing," says Lewis, "if they can do it in Mexico and other countries, why not trial it in New Zealand? There still seems to be a fear around meditation in New Zealand. They are lot more open in Latin American countries about using meditation as a tool to go inward."
Hopkinson adds: "To see these guys [in Mexico], it's obvious they are experiencing peace and joy. I haven't seen too much of New Zealand prisons, apart from the odd documentary, but these guys are looking a lot more cheerful than our inmates."
Leigh Marsh, Corrections' Manager National Operations, says some prisons have recently introduced volunteer-run meditation programmes. "At the Rimutaka Drug Treatment Unit, prisoners can take part in classes over a seven-week period that teach basic meditation techniques. Prisoners at Hawke's Bay Regional Prison are also able to take part in meditation classes run by the chaplaincy. The meditation programmes help teach prisoners coping skills and to release stress."
The idea for the film sprang from a book, Boundless, which Hopkinson published two years ago. In it he details a long and fraught journey to becoming a monk - not in the religious sense but as a teacher who has dedicated his life to making the world a better place.
A West Coast-born, hard-drinking, dope-smoking, highly-stressed businessman, he lost all his money in the 1987 sharemarket crash before working in the wild west that was post-Glasnost Russia in the early-1990s.
There he made enough money to come home and start the successful pet store franchise Animates.
He discovered Ascension meditation when, at a time when he was looking to de-stress, he picked up a pamphlet in a Wellington cafe. The practice is about learning four phrases that help to "let go of thinking and create space to reveal peace".
"You could be doing it while you're driving or working at your computer. In those situations, you're often not there - you're thinking of something else, something that happened five minutes ago, or something that's going to happen in 10 minutes.
"By using the technique you disengage from that and you're fully attentive to what you're doing, so the quality of your work, the quality of your engagement is just a multitude greater than normal."
After Boundless came out, Hopkinson was talking to a film-maker friend and raised the idea of making a reality TV show that showed people before, during and after learning to meditate. "He immediately said 'not enough sex and drama ... this would suit a documentary'."
Within 20 minutes, in January 2015, a plan was made to make a film. Hopkinson, 58, and Lewis, 56, emailed 500 meditation teachers in their global community looking for stories illustrating changed lives through meditation.
The overarching message, Hopkinson says, is that "peace is possible for individuals and communities. It's obvious for the people in the film and we're proposing that it's possible for the total population."
And yet, despite the evidence on the transformative power of meditation practice, Lewis acknowledges there is still a fear factor around it.
She experienced it herself as she dabbled in mindfulness techniques before meeting Hopkinson and following his lead.
"When I looked at learning these techniques I had this conditioning: 'Was it a cult, was it a religion?' I was fearful of those groups. And I think that's the problem in New Zealand - we don't understand it and we have those preconceptions that there are religious groups around the world that have done weird and wacky things."
Hopkinson adds: "There's no belief system at play here, it's just a tool to let go of the thinking - which induces stress, fear, worry and sad ess - and reveals the peace and stillness in each of us."
Lewis says: "Both Greg and I were tortured businesspeople, we were stressed, working hard, the chatter in our heads was starting to dominate our experience of life and that was very downward-spiralling.
"I got to the point where I thought 'I've had enough of this, there has to be a better way to live' and I started reading a lot of books and investigating this still, silent space everyone was talking because I seemed to be moving further away from it.
"Greg had learned these techniques and he said, 'This is it, this is how you're going to experience it.'
"It wasn't something I'd ever contemplated, meditation, but it delivered what I was looking for, it delivered the experience of peace - there was more joy."
While modern life seems to ask more and more of people, finding time to mediate can seem like a luxury, but Hopkinson is convinced that time spent in silent focus improves things.
"Often women are interested in meditation but they think it's a selfish thing to do - because the idea of taking time out to meditate when you've got a family seems like a selfish thing - but what we're showing in the film is that it's actually a selfless thing.
"If you're around someone who's happy and joyous it rubs off on the people around them. But if a person is stressed that's a very constricting, contracting experience.
"One person letting go of thinking and revealing that peace not only has an impact on themselves but on people around them."
The film's name comes from the pair's belief that we can all choose to live differently.
"That's the whole premise of the film," Lewis says. "I know from my experience I didn't feel like I had a choice. I thought I had the drama and the angst and the lack of joy in my life until the day I died.
"But once I found that seed of possibility - that I had a choice to walk a different way in life - it changed my whole outlook."
Hopkinson and Lewis are so passionate about Ascension meditation they've given up their careers to become Ishayas, or monks, committed to making the world a better place one mind at a time.
"We got to a point where we were experiencing such a full life we wanted to shared it with others and help others to experience it," Lewis says. "That's why we've become Ishaya monks and dedicated our lives to shifting that consciousness on the planet."
Hopkinson says they are both fortunate to have been successful enough in business to be able to follow this path, but other monks they know are still working fulltime jobs and raising children.
He admits to getting odd reactions when he tells people he's a monk but "with Sally and I you wouldn't know we were monks - we talk like normal people, we enjoy a drink, we lead a normal life".
Choice will premiere in the prison on October 19 and will be screened at venues around New Zealand from October 30.
For screenings see: www.choicethefilm.com