The boglands stretching west of Ballivor across the Meath and Westmeath border are older than almost anything else in the Irish midlands. Bord na Móna began mechanised peat extraction at Robinstown, Ballivor in 1946, and the workers who came to cut and process the bog were digging into ground that had been accumulating its secrets for thousands of years. In February 2003, a machine operator at the Ballivor Bord na Móna works discovered exactly how deep those secrets ran – a peat screening machine surfaced the preserved remains of a man who had been lying in the bog since between 392 and 201 BC. Clonycavan Man, as he became known, showed clear signs of ritual killing. He was a high-status individual, well-nourished, with elaborately styled hair held in place with imported resin gel. He had been struck three times with an axe. His remains are now on display at the National Museum of Ireland in Dublin, in the Kingship and Sacrifice exhibition.

He was not the only presence on that bog.

For many years, workers on the early morning shifts – those on site at around 3am, when the surrounding countryside was dark and still – reported seeing a woman walking through the bog. She had long grey hair and moved without speaking to anyone, passing through the working site as though the machinery and the men simply were not there. She came regularly, and then, at some point, she stopped coming. Nobody who saw her was able to say who she was or what her connection to the bog might have been.

The bog itself offers no shortage of possibilities. In Irish tradition, bogs have always been understood as threshold places – neither fully land nor water, neither past nor present, the kind of terrain where the usual rules can loosen after dark. A site that preserved the sacrificed dead of the Iron Age for over two thousand years is not a place that gives up its atmosphere easily. Whether the woman in grey belonged to recent memory or something considerably older, nobody who worked those early morning shifts could say.