Psychedelic Ceredigion-based stage musical Operation Julie is returning for a UK tour.

Over four decades ago, rural west Wales was at the centre of the greatest drugs bust in history.

The police investigation, Operation Julie, resulted in dozens of arrests and the discovery of LSD worth £100 million.

This spring, the hit musical show of the same name from Theatr na nÓg and Aberystwyth Arts Centre returns to explore the story from both sides of the drugs divide – the police, and the hippies who settled in Ceredigion hoping to spread their ideals in a changing world.

The co-producers are thrilled to announce that the original cast and creatives return for a limited six-week tour visiting theatres across the country.

Operation Julie is a musical play packed with songs, drama and comedy, telling the extraordinary story of what happened in and around west Wales in the mid 1970s when hippies settled in the area seeking a new way of living fuelled by acid and an alternative attitude.

When a chance clue is discovered following a car accident, the local constabulary works with detectives from across Britain to uncover what turns out to be the biggest stash of acid ever found, taking out up to 60 per cent of the world’s LSD market at that time.

Among the main protagonists are Richard Kemp and Christine Bott, a couple living near Tregaron who find a way of making the purest LSD the world had ever known, and roguish dealer, Smiles, based in Llanddewi Brefi.

Theatr na nÓg and Aberystwyth Arts Centre’s version of events tells the story from both sides of the law, with writer and director Geinor Styles meeting and interviewing a variety of people from that time, including one of the main acid dealers, Alston ‘Smiles’ Hughes – who was a key part of the LSD chain from his modest home in Llanddewi Brefi – and Anne Parry, the wife of the late Detective Sergeant Richie Parry.

Operation Julie is a musical play, a format favoured by the theatre company.

Greg Palmer is Operation Julie’s musical director and he discussed Smiles’ psychedelic musical tastes and the records that influenced him during the period of creating the play.

“Smiles has referenced a number of bands from that era – Caravan, Hawkwind, Incredible String Band,” he said.

“I’ve been very keen from the beginning of the process to have the sound world of the play reflect those musical trends, including great Welsh bands of the time Budgie and Man.”

Speaking today, Alston ‘Smiles’ Hughes says the acid movement was as much about a sustainable lifestyle and a commitment to saving the planet, as it was about psychedelic trips.

He said: “We were raising the flag and saying look, look, this is an emergency. [Humans] were spending the world’s capital, we weren’t living off the interest, we were spending the capital. And look at the state of the world now. They should have listened – they should have bloody listened… Then [in the 1970s], there was still the time to change. We could have changed lots and lots of things about society, and instead we went the other way, it just went into this global consumerism.”

Smiles hopes the play reflects the seriousness of the cause of that time, but also the joy of living through an exhilarating period: “It was wonderful. We had so much fun, you can’t believe it!”

The show returns to Aberystwyth Arts Centre from 3 to 13 April before touring to The Riverfront Theatre & Arts Centre, Newport (17 to 20 April), The Lyric, Carmarthen (24 to 27 April), Theatr Brycheiniog, Brecon (1 to 4 May), Pontio, Bangor (15-18 May) and the Crewe Lyceum Theatre (22 to 25 May).