On David's descent, he loses communication with the control tower and is forced to make a crash landing on a floating island populated by triffids.

Manhattan, a secure and self-contained community like the one on the Isle of Wight, appears at first glance to be a utopia seemingly untouched by the triffid catastrophe.

David quickly falls in love with his tour guide, Kerris Baedekker, who is one of the hundreds of daughters of General Fielding, the primary ruler of the city.

In order to rescue Christina and Kerris from Torrence's headquarters in the Empire State Building, the Forresters unleash thousands of triffids into the city, some as gigantic as sixty feet tall.

At the end of the story, it is revealed that the great blackout was caused by interstellar dust, and that even though it continues to wreak havoc on the global climate, people everywhere are still surviving.