Director Edel O’Mahony and scriptwriter Andrea McCartney introduce Dr Marie Cassidy Investigates Ireland’s Last Witch Trial, their new documentary exploring the 1711 trial of eight women accused of witchcraft, which premieres on RTÉ One Thursday 29th October.
It’s May 2026 and we are driving on a sunny weekday afternoon to the Islandmagee Peninsula, twenty miles north of Belfast.
As the waters of Larne Lough, the body of water which separates Islandmagee from the mainland, comes into view the question arises, what do we believe really happened here on this remote spit of land back in 1711?
The history books tell us that a young Presbyterian woman named Mary Dunbar was showing all the signs of demonic possession. Over a period of days, she named eight local women as witches, claiming they were responsible for her torment.
The people of Islandmagee, at that time mostly Presbyterians of Scottish descent, believed Mary’s accusations and the eight women were arrested, put on trial and found guilty. They are on record as fiercely protesting their innocence in court.
Today the peninsula is a tourist attraction for visitors to the Gobbins, a cliff walkway suspended over the Irish Sea.
Dr Marie Cassidy (centre) with Witches of Scotland podcasters and authors of To Kill a Witch
(L) Zoe Venditozzi and (R) Claire Mitchell KC
Yet, there are traces of its past written into the landscape; stone built cottages clinging to hillsides, churches dating back to the 1500s, and a landmark steeped in folklore: the Witches’ Rocking Stone, a boulder overlooking Brown’s Bay.
The story goes that the accused witches danced around it on moonlit nights.
As we reach the Rocking Stone, the bay below is busy with sunbathers and sea swimmers and it is hard to imagine that a witch hunt had once torn this community apart.
We hope that our film challenges the established narrative of the times surrounding witches and witchcraft.
We chat about the eight accused women who were variously reported as being arthritic and scarred and who drank and smoked and swore. As we learn during filming, any woman who was mouthy or even a little bit different was more vulnerable to being named as a witch during that time. And reflect that we could easily have ended up amongst the accused.
The trial is well documented and while Andrew Sneddon’s book Possessed by the Devil, the Real History of the Islandmagee Witches is an invaluable source of inspiration (as is Andrew himself) we wonder whether taking an approach which examines the case through a 21st scientific lens might offer a fresh perspective.
Marie in The Linen Hall Library in Belfast, examining existing evidence of the trial.
Bringing Dr Marie Cassidy, Ireland’s former state pathologist, on board as presenter allowed us to do just that.
In our very first conversation Marie’s eyes lit up at the mention of the sulphur which was reported by accuser Mary Dunbar and visitors to her bedside. Straightaway she suggested that exposure to sulphur can cause nausea and affect vision. Might that have led 18th century minds devoid of scientific knowledge to blame witchcraft for the symptoms Mary was experiencing?
She also introduced us to Professor Michael Gilchrist of UCD who set up an experiment to show the potential long-term effects of the punishments the witches endured in the wake of the trial. The results were both revelatory and harrowing.
And Marie had a very enlightening conversation with parapsychologist Dr Ciarán O’Keeffe, who cast his sceptical eye on some of the supernatural phenomena that was claimed to have taken place.
As state pathologist Marie dealt with many cases involving injustice towards women. She brings that same compassion to these eight women convicted of witchcraft in the last trial held in Ireland centuries ago.
We hope that our film challenges the established narrative of the times surrounding witches and witchcraft. But more importantly we hope it redeems the accused as women who were unfairly singled out and who protested noisily against the witchcraft accusations levelled against them.
Dr Marie Cassidy Investigates Ireland’s Last Witch Trial, RTÉ One, Thursday 29th October – catch up afterwards via RTÉ Player.