In 1983 Fergus Pryng, an idealistic young naturalist, was sent to survey Lanna, remotest of all the Scottish islands, which had never been surveyed before, and discovered there something so remarkable that it would have caused a global sensation – had he disclosed it. But Fergus did not tell the world of his discovery. Instead, he devoted his life to keeping it a secret, for 17 years, sacrificing his career, his marriage and his happiness – until the threat of nearby deep-sea oil development forced the astonishing truth out into the open, with ultimately catastrophic results.

What made Fergus keep his secret, and whether or not he was right to do so, are the questions Michael McCarthy makes central to this extraordinary story, because they go to the heart of one of the key issues of our time – the increasingly tragic nature of the human relationship with the Earth. Fergus The Silent highlights this issue in a particularly acute way, in the story of one singular and solitary individual with an unquenchable love for the natural world, himself a tragic figure whose fate is unforgettable.