It was a fortunate experience for me to re-read The Plague by Camus in the class when I was in the first grade of the masters programme. Personally, I was into his works when I was twenty-year-old, though we do need patience to read through. In fact, I remember The Plague had been really hard burden to read for the first time as well as when, of course, I read again some parts of it in French.
The city is blockaded as the Plague is prevailed. I see that the story is a conditional novel which is figuratively told as a representation of blockade of Paris by Nazis. That is a distinctive epoch-making attempt in spite of a heap of works as such written by lots of authors, but, even in the case of Meursault in The Stranger, who is richly-drawn, Camus succeeds in going deep inside of him (the final monologue) in order not to depict men in an indifferent way. Actually the characters like Rieux, Tarrou, are well drawn to the extent of relating their precise background, and one of the inevitable problems is, under such circumstance, how ones behave, whether such behaviour is good or evil and can be measured with a general moral or not. Because it is a novel which is related to condition of human mind under particular circumstance like a war.
Besides, it might be interesting to consult the theory of absurdity to which Camus devotes himself or works of Kafka. The Myth of Sisyphus is crystallised as The Plague. It is impossible to annihilate the plague artificially like Sisyphos carrying the huge rock, so that the more people fight, the more a number of dead increases. But Hell-like days passes without their noticing. There's no cause, but such continual connection is just absurdity Camus shows.