The figure at the centre of this work is the artist carrying the carcass of a sheep washed down the Severn and deposited on the beach at Penarth, just south of Cardiff docks and across the Severn estuary from Hinkley Point nuclear power station.

In the late 1890s, the English Impressionist Alfred Sisley painted bright views of the Bristol Channel from the cliff above Penarth beach. Terry Setch takes a different approach, treating the beach less as a scenic resource than as a perpetually evolving collision between nature and human industry. For thirty years now, he has been dragging his canvasses right out onto the beach, and including materials found there into the texture of his works. The memory of Sisley's unspoiled world persists in Setch’s paintings, but it is now mixed up with old cars, rubbish and other industrial debris. Once Upon a Time there was Oil III incorporates oil spilled from the tanker Amoco Cadiz, which ran aground off the shore of Brittany in 1978.