The story is set in the hot and humid Caucasus, in a seaside town on the Black Sea, among the small Russian community of officials and administrators living away from Russia itself. The town is a sort of "colonial" backwater.
The story has two elements. One is the relation between Ivan Andreich Laevsky and Nadyezhda Fyodorovna, lovers who have run away to the Caucasus. Nadyezhda is Laevsky's married mistress - she has run away from her husband and the two are trying to build up a new existence in this faraway place. They can't marry because a separation was legally impossible in those days. Of course, their relation sets tongues wagging among the community - the majority of the residents shun their improper courtship. On top of that, Laevsky no longer loves Nadyezhda, as he confides to his friend Samoylenko, a jovial doctor. He doesn't even tell her the news that her husband has recently died, so they could marry. Laevsky has a weak character: he drinks, gambles, and lacks direction. He is the type of the "superfluous man" and only perfunctorily performs his duties as a minor bureaucrat. As he neglects Nadyezhda, she has grown bored and has started flirting rather dangerously with other men.
The second element is the hate relation between Laevsky and the scientist Von Koren. Von Koren is a follower of social-Darwinism and the philosophy of Nietzsche - he feels that Laevsky's slovenly lifestyle is worthless. In fact, Von Koren feels killing Laevsky would be beneficial to society, an act of natural selection. Here he shows himself a gruesome predecessor of the 20th c. Nazis. Von Koren's dislike builds until he formally challenges Laevsky to a pistol duel. Chekhov has made the feelings of hatred between these two men, the rigid disciplinarian and the apathetic immoralist, very tangible.
The tension of the novella steadily increases until finally the duel takes place. Neither men is slain, but Laevsky has been grazed by Von Koren's bullet. His near-death experience leads to a psychological catharsis and leads him back to Nadyezhda. He realizes she is all he has... He marries her and starts working seriously to pay off his debts as well.
Typical for Chekhov, there are no clear heroes and villains in this novella, all characters are flawed, if not distasteful - but isn't that like real life? There is nothing human about the cold and hard Von Koren. Laevsky suffers from his apathy, Nadyezhda wastes her life in vain flirting. The town doctor, Samoylenko is good-hearted but useless, and so on.
Also typical for Chekhov, there is no clear plot - again, as in real life. There are no clear judgments either - Chekhov is not a preacher - he said it is the task of the artist to raise questions, not to answer them. And so it is - that is why The Duel is a masterwork that will continue ringing in your head for a long time.
The Duel was filmed in 2010 by Dover Kosashvili and with Andrew Scott, Fiona Glascott and Tobias Menzies.