A new virus strain has infected rice crops in
East Asia causing massive famine; the virus is also revealed to be found in the UK but because of its selectivity does not affect the country's agriculture. After the introduction of a new pesticide, developed in preference to breeding resistant crops, a mutated virus appears and infects the staple crops of West Asia and Europe such as wheat and barley—all of the
grasses (thus the novel's title). It threatens a famine engulfing the whole of the
Old World, while
Australasia and the Americas attempt to impose rigorous quarantine to keep the virus out. The novel follows the struggles of engineer John Custance and his friend, civil servant Roger Buckley, as, along with their families, they make their way across an England which is rapidly descending into
anarchy, hoping to reach the safety of John's brother's potato farm in an isolated
Westmorland valley. Buckley, having advance warning of the government's plot to
hydrogen bomb major cities, alerts Custance to evacuate. Picking up a travelling companion, a gun shop owner named Pirrie, after an attempt to procure arms, they find that they must sacrifice many of the aspects of the morality they held before the famine in order to stay alive. At one point, when their food supply runs out, they kill a family to take their bread, John justifying it with the belief that "it was them or us." Before reaching the valley, John takes in a large group of peaceful survivors. The group later survives encounters with a violent biker gang and soldiers attacking a farmhouse. After arriving at the valley, they find that John's brother is unable to let them all in to the heavily defended valley. Pirrie prevents John from taking only his immediate family into the valley; instead, the group takes the valley by force. Pirrie and John's brother are killed; John takes possession of the valley. ==Adaptations==