Francis Saxover and Diana Brackley, two scientists investigating a rare lichen, discover it has a remarkable property: it retards the aging process. Francis, realising the implications for the world of an ever-youthful, wealthy elite, wants to keep it secret, but Diana sees an opportunity to overturn the male status quo by using the lichen to inspire a feminist revolution. As each scientist wrestles with the implications and practicalities of exploiting the discovery, the world comes ever closer to learning the truth...