It may best serve our purposes to tell what triffids actually are. Triffids are odd, interesting little plants that grow in everyone's garden. Triffids are no more than mere curiosities until an event occurs that alters human life: what seems to be a spectacular meteor shower, turns into a bizarre, green inferno that blinds everyone and thus renders humankind helpless. What follows is even stranger: spores from the inferno cause the triffids to suddenly take on a life of their own and they become large, crawling vegetation with the ability to uproot itself and roam about the country attacking humans and inflicting pain and agony.

William Masen somehow managed to escape being blinded in the inferno (yet he was still hospitalized, eyes bandaged following surgery), and he is now one of the few surviving human beings who can see and who can avoid being attacked by the triffids and who just might be able to save mankind from the terrible chaos as well as possible extinction.