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...