This book is fantastic and frightening, but entirely plausible. It doesn't just seem scientifically possible, but its characters are living people shaken out of the civilization they know into the horror of a world dominated by triffids. The triffids are grotesque and dangerous plants, over seven feet tall, originally cultivated for their yield of high-grade oil. So long as conditions give the mastery to their human directors, they are a valuable asset to mankind. But when a sudden universal disaster turns those conditions upside down, then the triffids, seizing their opportunity, become an active and dreadful menace. The story of what happens is told here by one of the few people lucky enough to escape the disaster.

At the end of The Day of the Triffids, the hero, Bill Masen, his wife, and four-year-old son leave the British mainland to join a new colony on the Isle of Wight. The Night of the Triffids takes up the story 25 years later. David Masen, the now grown-up son of Bill, is a pilot, still searching for a method of destroying the implacable triffid plant as it continues its worldwide march, seemingly intent on wiping out humankind. David eventually manages to reach New York, where a very different sort of colony has been set up, a colony whose members seem to be immune to the triffid string and where David comes face to face with an old enemy from his father's past.

Twenty-five years ago civilization collapsed and the triffids replaced mankind as top species. Survivors cling on, confined to islands or triffid-besieged strongholds, yet the future looks bleak. On the Isle of Wight, Bill Masen, hero of The Day of the Triffids, continues to hold his small community together, but time is against him and the enemy seems invincible. Is humanity’s time at an end?