In the sixteenth century, as it is now, the Burren, on the western seaboard of Ireland, was a land of grey stone forts, fields of rich green grass and swirling mountain terraces. It was also home to an independent kingdom that lived peacefully by the ancient Brehon laws of their forebears.

On the first eve of May, 1509, hundreds of people from the Burren climbed the gouged out limestone terraces of Mullaghmore Mountain to celebrate the great May Day festival, lighting a bonfire and singing and dancing through the night, then returning through the grey dawn to the safety of their homes.

But one man did not come back down the steeply spiralling path. His body lay exposed to the ravens and wolves on the bare, lonely mountain for two nights . . . and no one spoke of him, or told what they had seen.

And when Mara, a woman appointed by King Turlough Don O'Brien to be judge and lawgiver to the stony kingdom, came to investigate, she was met with a wall of silence . . .