Bill Masen wakes up one morning in his hospital bed. His eyes are completely bandaged after an eye operation so he is unable to see. He immediately notices how still and quiet everything is. Having taken off his bandages, he discovers that both inside the hospital and out, the majority of the population (who watched a display of startlingly bright comets in the night sky the previous evening) have all gone blind, and realises that there is a terrifying new enemy for humankind to contend with. This is his thrilling, chilling and enthralling story....

When Bill Masen leaves hospital and goes into the centre of London, he finds that looting is rife as people are grabbing anything from the shelves of shops that they think they might find useful - mainly food.

While surveying the scene he comes across an attractive young woman who also wasn't blinded, Josella. Together they return in her car to her parents' home, only to discover everyone at the house has been murdered by the Triffids. The Triffids are walking plants which carry a vicious and lethal sting. Bill used to have one in his back garden, but far from being completely harmless they have now developed and are threatening to take over the world. They are also strongly linked to the mysterious comet shower.

Bill has an advantage over other surviors in that his job had involved him researching the Triffids. In fact, it was a Triffid sting that was one of the reasons he had been in hospital on the night of the comets, and this incident saved him from blindness. Together, Josella and Bill, whose bond to each other is growing, join a group of people, many of whom are blind but some of whom can see, with plans to head into the country...and their true struggle begins.