Bill Masen is a biologist working with triffids, a newly-engineered plant that provides valuable chemicals but that also has a powerful sting capable of killing a human. The most amazing thing, however, is that they are able to walk about on their three stems and communicate with each other by tapping branches together.

Bill is recovering from an accident in which he got triffid poison in his eyes. Bandaged, he is unable to see the unusual meteor display over London one evening. He wakes up the next morning to silence. Unable to summon anyone to his hospital room, he tears off his bandages to discover that everyone around him has been struck blind.

As the days pass, people begin dying, unable to take care of or feed themselves. And the triffids seem to be getting more aggressive. Then Bill finds Josella Playton and rescues her from a man who was using her as a seeing-eye dog. Blacked out from a drunken spree, Josella had also kept her sight. It soon becomes apparent that there are a scattered few who can still see. Many of them band together and plan to develop a colony where civilization can get a new start. At first, it seems cruel to abandon the blind, but it soon becomes apparent that there are far too many to help, although a few who have been blind since birth and have learned skills are allowed to join the group.

One man, Coker, wants to help them all. He raids the colony and takes several of the members, including Bill, handcuffing them to blind men and assigning them to sections of the city to find food and shelter. But disease soon strikes (from contamination from all the dead bodies) and Bill’s group dies off. Bill escapes and goes looking for Josella. His search lasts for several months, part of it teamed up with Coker, who now realizes his methods would never work. They find several small groups, but most of them without the organization to last long.

Bill remembers a country house that Josella mentioned shortly after they met. He goes to seek her there, rescuing Susan (a 10-year-old girl) from triffids on the way. They find Josella at the house with a blind couple and a pregnant woman. The six of them set up a home, keeping the triffids (which gather in huge numbers) away with fences and starting a farm. After six years, they are contacted by a member of the colony, now set up on the Isle of Wight where they have destroyed all the triffids. Bill’s group determines to join them, but before they leave, they are visited by a man who leads a group determined to rule by military force. Bill sabotages their vehicle and lets the triffids into the farm while taking his group, which now includes two babies (including one he had with Josella), to the Isle of Wight.

Written six years after WWII, when the Cold War was in full swing and the threat of nuclear war and biological weapons seemed very real. It makes for a good, old-fashioned sci-fi suspense story. Well-written and fun to read.