In late 20th century Great Britain, a spectacular
meteor shower unexpectedly renders most of humanity blind, leading to the collapse of society overnight. Unaware of this, Bill Masen (
John Duttine) has retained his sight due to being in hospital with his eyes bandaged at the time of the shower. Bill works on a
triffid farm, where the mobile and carnivorous plants are cultivated for their oil with their deadly stings retained, which improves the oil quality. Prior to the story, Bill was stung by a plant and even though he was wearing protective clothing, some of the poison got into his eyes. In the hospital he tentatively removes the bandages and gradually discovers the catastrophe around him. Bill rescues Josella "Jo" Playton (
Emma Relph) from her blind captor and learns that she was asleep during the meteorite shower and thus kept her sight. They encounter a small band of sighted survivors who have decided to leave London and establish a community elsewhere to begin rebuilding civilisation. They are initially opposed by sighted Jack Coker (
Maurice Colbourne), who wants them to stay in London and help the blind, not abandon them. When the others reject his scheme, he and a few sighted helpers capture some of the group, including Bill and Jo. He assigns each to a different group of the blind. Bill is handcuffed to two of his charges to prevent him leaving them. The triffids get loose and run amok amongst the helpless blind population, slaughtering and feeding on them. Between the triffids and a mysterious deadly disease, most of Bill's group eventually die; the rest scatter. Bill starts searching for Jo and teams up with Coker, who admits his plan did not work as he had hoped. They drive through the English countryside and encounter part of the group that had left London. The group had split after a disagreement over morality: the ones who stayed behind, led by Miss Durrant (
Perlita Neilson), refused to accept that
polygamy was necessary to repopulate the world. After more fruitless searching, Coker decides to return to Miss Durrant's community. Bill meets a young sighted girl, Susan, and she accompanies him. Finally, he recalls that Jo had spoken of a place belonging to her friends in the
Sussex Downs. There he is reunited with her and after erecting a protective fence around the farm to keep out the triffids, they settle down and start raising a family. Six years pass, and one day Coker shows up in a helicopter. Miss Durrant's group had been wiped out by the disease but the other faction had secured the
Isle of Wight and exterminated the local triffid population. With the situation gradually deteriorating where they are, Bill, Jo and the blind friends who own the farm, as well as the children, prepare to join them. Before they can leave, several uniformed men arrive in an armoured car the next day; they are part of an organisation that is setting up a
feudal society, with the sighted as the new
aristocracy. In their setup, one sighted person is in charge of ten of the blind. They plan to assign more blind people to Bill and Jo, and take Susan away to learn how to care for others. Bill gets the soldiers drunk and sabotages their armoured vehicle. Early the next morning, Bill and the rest of the group drive away, leaving the gates open for the besieging triffids as they approach the soldiers. ==Cast==