High school students are supposed to read Canticle for many of their humanities classes, but they rarely do and those who have seemed to have been unaffected by it. Of course, maybe it's the gas-pumpers I grew up with, I dunno'.
The book takes place in three stages. The first stage is a bit after a planet-devastating nuclear war. Knowledge and writing have been forbidden in a vicious anti-intellectual pogrom (curious -- do read Carl Sagan's The Demon-Haunted World and try to convince me that Canticle isn't a potential result of what's described in Sagan's book) the effects of which have just barely avoided small groups of monks engaged in the preservation of as much knowledge of the past as possible. The second stage reveals a new culture of man, rising up from the wreckage of Earth with the knowledge that the monks, after a fashion, re-released. There are hints of the old jealousies and sins of Man, but there's hope, too. The third stage of Canticle reveals that no matter how much Man learns, the future only contains self-destruction and immolation. There is just a hint that something other than Man, that something purer than Man will now make its attempt on the Earth, but Man, as a race, is pretty much gone.
That a sequel to Canticle exists is, to me, most astonishing. Where do you go after the destruction of the entire human race? Ah well, I'll just have to read the damn thing...