Thousands of visitors go to the Italian Chapel in Orkney every year, witnesses to a series of remarkable acts of transformation. Among these are the Churchill Barriers nearby, straddling the ocean to link a number of Orkney's southernmost islands to its mainland. Constructed to protect Britain's naval fleet in Scapa Flow during World War Two, its builders included a group of Italian soldiers imprisoned in this bleak and windswept part of Scotland. In the course of this, they not only played a part in changing Orkney's way-of-life forever but also transformed a simple Nissen Hut, constructing through their labours a place-of-worship that still stands till this day a remarkable symbol of their identity and faith. And On This Rock tells the story of the strength and tenacity, laughter and tears of the men who built the Italian Chapel, showing how spirits defeated and despondent during years of exile were lifted by its creation. It does this with its own artistry and grace, using folk-tale and myth to provide a fitting counterpart to the wonder and beauty of the building that inspired it.