Bill Masen is lying in his hospital bed as he recovers from an accident with a triffid, a poisonous and carnivorous plant, that has left him temporarily blind; what he doesn't realize is that, overnight, the world has changed.

It slowly dawns on Bill that something terrible has happened overnight, and while leaving the hospital, meets and forms a bond with Jo Payton; Jo also missed the comet's display and so, like Bill, has not suffered the blindness visited upon others.

Bill and Jo sight a signal from the University Tower where survivors have formed; they both face a difficult moral decision about helping others.

Now separated from Jo, Bill is held captive by Coker and forced to do his bidding.

Bill and Jo have settled into life at the farmhouse, becoming self-sufficient and fending off triffid attacks with flame throwers.