This is a second printing of Plague by Graham Masterton, published in 1977 by Ace Books.

From the publisher:

At first the rules were simple: quarantine the city, and let the plague die. So men and women closed their doors, and lived in lockdown, fighting for survival against a disease as contagious and destructive as the Black Death. A disease for which there was no known cure.

But the plague did not die. And so, at lunchtime on a Friday afternoon, the President announces the new rules. Every American should take up arms to protect the disease-free zones. Anyone attempting to leave the plague-zone must be shot.

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