"The whole thing about Santaroga boils down to this - Why were we forced to close our branches there?  Why won't even one Santarogan trade with an outsider?  That's what we want to know.  What's this Santaroga Barrier which keeps us from doing business there?"

These are the questions that Gilbert Dasein sets out to answer.  Once he is actually in the isolated community of Santaroga, Dasein senses a strange, mysterious quality that permeates the very essence of the town.  The people have lost all personal identity; they have become masks for something that is the same in all of them...

Soon Dasein realizes that the secret of Santaroga lies in the nature of a potent substance called "Jaspers" - and that he is trapped in Santaroga, unable to turn back....

Santaroga seems to be nothing more than a prosperous farming community, but there is something different about it. It has no crime at all. Outsiders find no houses for sale or rent in the valley, and no one ever moves out. Maybe Santaroga is the last outpost of American individualism. Or maybe there is something extraordinary at work there - something far more disturbing than anyone imagines.