Wales has reached the apex of her industrial clamour. But young Tom Mortymer, son of rich industrialist Iestyn Mortymer, has turned his back on his inheritance, exchanging the bell-clang and fire of his Upper Forest Tinplate Works in Morriston for the simplicity and wanderlust of a gypsy existence with his young Romany wife, Jen Wildflower. In time they come to settle on Flatholm Island where they become a refuge for the animals. Self-sufficiency is their ultimate goal; the substantial income from tinplate is ignored. But their simple idyll does not last. They are aware of a strange malevolence towards them.One frightening incident follows another until it is clear to tom and Jen that they will have to abandon their home and return to Cefn-Ydfa, their mansion in Maesteg. Their decision coincides with the arrival in Cardiff of Jethro Mortymer, Tom's uncle - whom he had long believed dead. Would Jethro be able to shed any light on Tom and Jen's continuing nightmare?