Most great stories have a strong plot line. That comes from how the characters are related to each other. The classic way of doing this is a triangle. The skeleton of the plot can be diagrammed as a social network.
A network diagram may look static, but a good structure is bursting with energy. It is the tensions in the network-- with its positive and negative links-- that drive the plot. Great literature is a version of network sociology.
The Great Gatsby is considered a major classic above all for its tight plot structure. It is also the great self-portrait of the Jazz Age, and has been filmed many times for its over-the-top party scenes, not to mention the reckless driving around in flashy convertibles.
What makes it work, though, is the way it is structured: two interlocking love triangles closely packed into a short book.
The love triangle is a very old plot device that doesn’t show any sign of wearing out. A love triangle is a tense network because there are two very strong ties-- the two rivals with their love object-- plus a strong negative tie between the rivals.
How do authors and film-makers get so much mileage out of it? Aside from inserting a love triangle into different social classes and historical settings, there are three main possibilities:
 Vary the focus on different members of the triangle. Take one of the rivals as protagonist; or zoom in on the emotional struggles of the person in the middle; or give everybody equal time; etc. Make the conflict quick or long drawn-out; highlight being faithful or flighty; end happily or tragically.
 Link two or more triangles together. (The Sun Also Rises; The Graduate)
 Locate the point of view in an outsider to the triangle. If the outside narrator has to discover what is going on, it adds mystery to the inner tension of the triangle. The driving force becomes finding out what is happening, combined with the unresolved plot tension of what is yet to happen. (The Great Gatsby)
A simple triangle: Casablanca
The structure doesn’t have to be complicated to make it work. One of the most famous films of all time, Casablanca, consists of one simple triangle.
The story is told almost entirely from the POV of Rick, the American bar-owner. There is his on-and-off romance with the beautiful Ilsa, explained in flashbacks after she walks into his saloon in Morocco with another man. The man turns out to be Ilsa’s husband, Victor Lazlo, heroic leader of the anti-Nazi underground throughout Europe.
Unlike many love triangles, there is no conflict between the two rivals; they respect and even like each other. So the plot tension is driven mainly by the love-hate relationship between Bogart’s character and Ingrid Bergman’s character. Since Bogart has the documents that will enable a couple to get out of Casablanca and escape the Germans, Ilsa tries to get them from him by various appeals. Finally she pulls a gun on him; when that doesn’t work, Ilsa simply breaks down and tells him he’ll have to make the decisions for both of them from now on. End of triangle; end of plot tension.
Well, not yet. The effect of the minor figures surrounding the triangle now takes over driving the plot.
The antagonistic part of Lazlo’s network are the Nazis. Bogart starts out neutral, the cynical tough guy only out for himself. But almost everyone who works for him in the saloon is in the anti-Nazi side, and Bogart gets pulled into protecting them. A third part of the penumbra are the Vichy French, like the bar women who consort with the German soldiers. There is also Rick’s quasi-friend, the chief of police Captain Renault (Claude Rains’ character), who is likewise cynical and sophisticated, but with a light and charming manner. Through a series of symbolic confrontations with the Nazis, all provoked by Lazlo, the fence-sitters start standing up for the Resistance. Bogart is pulled along by the minor part of his network--- all secondary characters and bit parts, but Rick as famous saloon-keeper is the patron of a network, which cumulatively adds up to a strong tie. In the end, Bogart goes over to the Resistance and brings his counterpart Captain Renault along with him.
Rounding it off at the end is the love story. The triangle rivalry isn’t quite over, although it takes a new twist. Bogart and Lazlo take turns showing how noble they are. Lazlo offers to give up Ilsa so that she can escape; Bogart finally sends her off with Lazlo so that she can support him in the great work he is doing for the cause. In the high-angle perspective of network structure, the woman at the hinge of the triangle is essentially passive, all the decisions being made for her by the men in her life. This is certainly a pre-feminist film. On the other hand, the ending does resonate with the join-the-fight message of this 1942 film: Bogart becomes the typical American soldier leaving his lover behind as he goes off to war, doing what a man has to do. Lazlo, who gets Ilsa, is not quite in the same category as a hero.
The Sun Also Rises: Multiple triangles around a hub
In Hemingway’s signature novel of Paris in the 1920s, The Sun Also Rises, a series of triangles centered on one woman make up both the atmosphere of “the lost generation” and the prime mover of the plot.
The central figure in the network structure is Lady Brett Ashley, a beautiful and wealthy widow, who lost her husband and her ideals in the war. In the novel, she is surrounded by past and present lovers, including:  Jake Barnes, a cynical American newsman;  Pedro Romero, the rising star of the Spanish bullfighting world;  Robert Cohen, a gauche young Jewish American;  Mike Campbell, another British aristocrat and Brett’s current fiancée, who drinks continually and views everything with cynical amusement.
We never do see things from Lady Brett’s POV, and only the network diagram brings out how central she is. * Take her out of the network and the whole story collapses. Instead, the narrator is Jake Barnes, who is both disgusted with Brett but can’t help carrying a torch for her, as the saying was. They were old lovers, supposedly idealistic ones, but he was wounded in the war and has become impotent, while everyone else centers their lives on their sex drives.
* There appears to be a punning allusion in her name: the British equivalent of the American Social Register that lists members of the hereditary wealthy upper class was called DeBrett’s Peerage. Hemingway is implying that she represents the topmost elite of the aristocracy, who have thrown themselves into the new 1920s scene of partying, drinking and sexual affairs, like Fitzgerald’s rich young people in America.
Structurally, Jake’s impotence enables Hemingway to let one of the participants in the triangles conduct us through the story-- not that anything is mysterious for Jake, but he is dragged along nevertheless in the feeling of networked doom that Hemingway manages to evoke. Jake knows all the other characters, and in fact the novel starts by Jake talking about how Robert Cohen was a boxing champion at Princeton; and how Cohen is always hanging around his newspaper office. This sounds like starting off on a tangent, but by the end it becomes clear that it is structurally important. Looking at the network where men radiate out from Lady Brett like spokes of a wheel, the plot question is: where is a jealous triangle going to form?
The answer is: Cohen sees Lady Brett in the Paris cafe whirl, and she toys with him, while he becomes obsessed with her. Moving on with the whole group of holiday-makers into Spain, Brett picks up with a beautiful, slender young bull-fighter. Jake is even more sorry to have made this connection for her, because he knows how much bullfighters need to avoid distractions and concentrate on their craft; but there is no stopping Lady Brett. Cohen finds out about this affair, and beats up the bull-fighter in a rage-- a boxing champion being the more dangerous to human beings, especially when he doesn’t understand the code that Hemingway insiders live by.
The story ends with Lady Brett calling on old reliable Jake to get her out of Spain-- a place where an older moral code still prevails and the lost generation’s affairs are barely tolerated. Jake Barnes is more like a real-life version of Bogart’s character in Casablanca, but this time life has no romantic endings, just real regret over what might have been.
The Sun Also Rises is the most serious, and most sociologically acute, of all Hemingway’s novels; and the only one structured around a love triangle.**
** Until Hemingway’s posthumous novel, The Garden of Eden, came out in 1986, 25 years after his death, and receiving little attention among his major novels. It is psychologically the most complex of all his novels, plotted around a bisexual love triangle: an attractive and creative young man; his wealthy young wife who wants to immerse herself in him so much that she tries to be the man; and a beautiful Frenchwoman who lets both of them make love to her. The ideal coupling breaks up as the wife directs the triangle more and more aggressively; the young man ends up with the Frenchwoman but without his ideals. Tersely written in the best Hemingway style, it reads like the enigmatic “Hills Like White Elephants” overgrown into a rainforest of love-cum-sex.
Interlocking triangles plus outside narrator solving mystery
The construction of The Great Gatsby is especially powerful. The network structure consists of two interlocking triangles:
Triangle number one:
Daisy, the golden girl, belle-of-the-ball, debutante of the year as of five years ago; now married to:
Tom Buchanon, rich inheritor of an old family fortune, athletic and domineering;
Gatsby, upwardly mobile from nowhere into splashy riches; the antithesis of Buchanan in being unrespectable and linked to the criminal underworld; but very good looking and personally dominant.
Left to itself, we can easily imagine how this triangle would work out. Although Daisy and Gatsby had a romantic affair when he was disguised by his army officer’s uniform, in the adult world respectability and money were bound to beat disrespectability and money. Sociological theory of marriage markets shows this from empirical data: marriages tend to be homogamous on as many dimensions as possible.
Fitzgerald’s inspiration was to link this rather standard old-rich vs. nouveau-riche conflict with a second triangle:
Tom Buchanon, the rich man:
Myrtle, a floozy from the working class, the lower class version of the flapper / party girl (of which Daisy is the upper class version);
George Wilson, Myrtle’s husband, a working class looser struggling to run a gas station.
Looking at the network, we discover that the center linking everything together is Tom Buchanon. He is not presented as a sympathetic character, but nevertheless if he is taken out of the diagram, the plot collapses.
Structurally, the central character is a plot-tension network does not have to be sympathetic; nor does much attention have to be directed at him or her. The pivot of the story is inescapable, and may well be last one standing at the end-- not only like Tom Buchanon, but Lady Brett Ashley.
Pivoting on Tom, the two triangles work themselves out at the same time:
If we take Daisy-Tom-Myrtle as one rivalry triangle, it ends in classic fashion, with Daisy killing Myrtle, her structural rival. Never mind that Daisy kills her by accident with a speeding car through a mix-up of whose car it is; and for that matter, that Daisy knows only that someone like Myrtle exists in her husband’s life although she doesn’t know who she is. Fitzgerald’s plot works with the inevitability of ancient Greek tragedy; the protagonists don’t need to know what they are doing, to bring the structure to its fated resolution.
The other triangle in Tom’s life ends with Wilson killing Gatsby, and then shooting himself. In other words, Tom gets his two male rivals to eliminate each other. This is arranged, half-inadvertently, but sensing an opportunity, by Tom, who tells Wilson (truthfully) who the speeding car belongs to. The rest of the triangles being eliminated, Daisy is back with her respectable rich husband, and they leave this sordid mess for somewhere else in the world, retreating into their vast fortune.
The two-triangle story, murders included, could have been told straightforwardly by an omniscient author or from the point of view of one of the main characters. Fitzgerald however adds a third layer:
This is his narrator, Nick Carraway. He happens to know the other main characters-- Daisy because she is his cousin; Tom because they were classmates at Yale; Gatsby because Nick rents the old caretaker’s house next to his mansion. Everybody drags Nick along with them, and reveals the backstage of their affairs. Tom takes him to the garage and to a drunken party with Myrtle and other flappers. Gatsby invites him to his grand parties, shows him around his mansion, takes him to lunch in New York with his underworld connections. And of course, Gatsby is cultivating Nick so he can establish the network link that will bring him and Daisy together, and launch the culminating action of the plot.
The outside narrator gets the early part of the story going, where the main interest is the parties Gatsby gives at his mansion, and all the speculation about who he is and where his money comes from. Nick Carraway is like a naive detective who has the mystery revealed for him. Nick grows in stature towards the end because he is the only person throughout the plot who learns the truth. He alone knows that Gatsby pretended he was driving the fatal car, to save Daisy from a murder rap. This raises Gatsby’s moral standing, but it also is the nail in the coffin of his affair with Daisy, since she can’t go off with a known murderer. (Even though she is a murderer herself; and her husband is indirectly.) So the naive narrator can present a moral judgment on what is going on. “You’re worth the whole damn bunch of them,” Nick says to Gatsby before he goes to the pool and is murdered. No need for Fitzgerald to preach; the structural arrangement of the POV does it for him.
The Graduate: Three consecutive triangles viewed from inside
Finally, look at the network structure of The Graduate, another famous film. This consists of three triangles, played in sequence:
First, Benjamin, a young Ivy League graduate moping around home, responds to the wife of his father’s business partner, Mrs. Robinson, and starts a clandestine affair. This is played awkwardly for comedy, until the other parents in the network pressure Benjamin into dating the Robinsons’ daughter Elaine. Benjamin finds her a respite from the pressures of his clandestine life, and falls in love, thereby setting up the first triangle. Most of the plot tension in this part is between Mrs. Robinson and Benjamin; structurally mother and daughter are rivals, but the mother can’t tell her that, and so her anger has to come out on the other link of the triangle.
The unusual twist is the mother-daughter rivalry over the same young man (a structural substitution for the father-son rivalry over the same young woman that is at the center of The Brothers Karamazov). In this sense The Graduate resonates with the sexual revolution of the 1960s. It also shows there are plenty more permutations possible in the old love-triangle formula, by shifting sexual taboos and gender preferences.
The second triangle develops when Benjamin finds Elaine has another boyfriend. This is Carl Smith, a medical student depicted only vaguely as good-looking, successful and conventional. Carl largely ignores Benjamin and the latter doesn’t even try to play the aggrieved rival; this leads to another comedy sequence in which Benjamin uses his naive gaucheness as a way of mocking Carl and importuning Elaine to marry him instead.
The third triangle is latently present from the beginning. Having an affair with Mrs. Robinson makes Mr. Robinson the aggrieved husband, and therefore Benjamin’s rival. This doesn’t come out until late in the plot-- as a device to retard the action of triangle number two, when Mr. Robinson shows up at Benjamin’s rooming house and threatens him with a lawsuit. Keeping this triangle latent also makes the point that Mr. Robinson is sort of a nothing; his wife has stopped sleeping with him so he is no real rival. Benjamin never gives him a thought, and literally tells him so, in a comedic apology that makes things worse. Structurally, Mr. Robinson is just one of the cliché-spouters that Benjamin perceives as populating the entire older generation; all the more reason why this triangle is not very important in driving the action.
The final action sequence is when Benjamin breaks into the wedding to Carl Smith, calls out Elaine, and successfully fights off the families and wedding guests to escape on a bus. This rounds off triangle two with a happy ending.
Structurally, triangle one has already played itself out when Benjamin leaves southern California, the site of his affair with Mrs. Robinson, and follows Elaine to Berkeley. In that sense, the plot sequence of The Graduate is rather simple; one triangle is succeeded by another, and it is all told from Benjamin’s POV. There is a brief period of linkage between the triangles, when Mrs. Robinson tries to alienate Elaine from him by telling her that he raped her mother. Surprisingly, Elaine gets over her outrage rather quickly. Is this a flaw in the plot? Perhaps so; but notice that Elaine’s actions in the sequence of triangles are much the same as Ilsa’s in Casablanca. The heroine emotes and vacillates in her triangles, but she lets other people decide things for her: taking her mother’s standpoint in the first triangle, then prevailed upon by first one man, then the other, in the second triangle. Despite the coincidence that The Graduate appeared as a film in 1967, when the 1960s counter-culture was becoming famous, it is not feminist viewpoint.
It isn’t even a counter-culture viewpoint. The irony is that some of the scenes were shot on the Berkeley campus (during production a year or two previously), but the rebellious long-haired counter-culture style is nowhere in evidence, and certainly not in the preppy Benjamin with his upper-class kid’s Italian sports car. In real life, Benjamin and Elaine of the late 1960s would not have gotten married; they would have smoked dope, joined a commune or at last cohabited, taken part in demonstrations and played around with revolutionary politics. The reason they don’t do any of these things is that The Graduate was initially a novel by Charles Webb, published in 1963 when the 60s still looked like the 50s; the author graduated from tweedy ivy league Williams College a few years earlier, and that is the atmosphere still shown in the movie. It is more The Catcher in the Rye, a 1951 depiction of existentialist alienation in an elite Eastern prep school. Benjamin is Holden Caulfield a few years older, and having discovered sex.
Triangles and sexual revolutions
Anachronisms in the setting don’t make that much difference for successful drama. The network structure of interlocking triangles is perfect for dramatizing sexual revolutions, with new sexual behaviors filling in the content. The first modern sexual revolution was the 1920s, when the old-fashioned marriage market overseen by parents was superceded by the flirtatious partying scene depicted by Fitzgerald and Hemingway. Both novelists were social observers, and their material came from both sides of the Atlantic, at virtually the same moment (1925-26). * The second sexual revolution of the 1960s and 70s became far more radical, challenging marriage by cohabitation, the gay movement, and feminism. This second sexual revolution received its iconic statement in The Graduate, not because it is an accurate portrayal of what was happening, but because the dramatic structure of a succession of triangles is so memorable.
* The best description of the revolution is Fitzgerald’s 1936 essay, “The Crack-up.” Fitzgerald named it “the Jazz Age,” but in the early 1920s, “jazz” did not mean music—it was a slang word for sex.
Great literature resembles network sociology. The basic forms are simple, but a lot of variations can be built from them.
One of the oldest dramas, Oedipus Rex, creates a shocker by making the network between a father, mother, and son. Shakespeare did something close to this in Hamlet. Dostoyevsky did a more complicated version in The Brothers Karamazov.
The variations are not exhausted. One new vein, just now being explored, is to a network of heterosexual and homosexual ties. (Imagine re-doing Jane Austen with gay characters coming out of the closet. You can expect to see this on the screen before long.)
How do writers create plots? One way is by rearranging the structure of successful old plots, and transforming them in the ways listed above.