It is over six months since the West Sussex community of Pentworth became isolated from the rest of the world by a mysterious force wall. Beyond the strange, dome-like barrier lies the unreachable world of the bleak steppes of Europe of 40,000 years ago. Equally unreachable are the visitors responsible for the creation of the force wall, sheltering in their UFO in a deep swamp. The visitors have largely ignored the imprisoned inhabitants with the exception of sixteen-year-old Vikki Taylor. She alone holds the key as to why the visitors have come. But the revival of ancient superstitions in Pentworth have made Vikki and her friends fugitives, accused of witchcraft. The Silent Vulcan opens with Pentworth on the brink of a bloody civil war between town and country and concludes with the visitors finally showing their hand and revealing the extraordinary reason for their arrival in their "Silent Vulcan".