Back in the 1920s, two dudes—Peter Keating and Howard Roark—finish architecture school and embark on their careers. Peter Keating graduates with top honors and goes to work for a hotshot firm in New York, headed by a dude named Guy Francon (best name ever, in our not-so-humble-opinions). Howard Roark gets tossed out on his rear and goes to work for a drunken has-been, also in New York. If you're thinking that this sounds like a prime situation for a reversal in fortune, you'd be correct.
Turns out Peter Keating is a bit of a poser and his ascent to the top of his profession involves blackmail, stealing people's work, shmoozing, causing an old dude to have a stroke (seriously), hitting on the boss's daughter, and getting Roark to do things for him. Roark, meanwhile, is a true individual, modernist designer (a lot like Frank Lloyd Wright), and his work is brilliant but unappreciated by the stupid public. Roark even gets sued for breach of contract after he refused to compromise on a building design, and he ends up broke and without clients.
lRoark eventually goes to Connecticut to work in a quarry for some cash and meets Dominique Francon, the icy-blonde journalist daughter of Peter Keating's boss. Got all that? Roark and Dominique have a violent sexual encounter shortly after meeting (read more about that in the "Steaminess Rating" section) and later embark on a secret (and psychologically screwed-up) affair.
Dominique proceeds to attract Peter Keating, and the two end up getting married, which is a truly bad idea. Keating abandons his true love Katie Halsey in order to marry Dominique for selfish reasons (money, prestige, etc.). Dominique decides to wallow in her misery about how much the world sucks and marries Keating as a bizarre sort of protest against society.
While all of this is going on a critic named Ellsworth Toohey (Katie's uncle) is systematically building up Keating while destroying Roark, since he's an evil communist and doesn't want bold individuals to succeed. Also, he may or may not be suffering from a massive inferiority complex and be something of a sociopath. What a dude, eh?
The architects continue to do architectural things and then Gail Wynand, media mogul and owner of The Banner newspaper, enters the scene. He basically buys Dominique from Peter Keating, giving Keating a posh commission in exchange for a divorce. Wynand then marries Dominique. Dominique continues her emotional affair with Roark and is now batting 0-2 in the husband department. Wynand and Roark actually bond and become friends, and the love triangle gets all sorts of weird.
Meanwhile, Keating turns into a loser (hey, we're giving you the Ayn Rand version here, completely without frills) and falls under the sway of Toohey, along with a lot of other characters, including Keating's ill-fated true love, Katie Halsey.
Finally Toohey tries to alter a building Roark designed for Keating (Keating was taking credit for Roark's design), and Roark blows the building up in an effort to preserve his artistic integrity… or something. There's a big trial and Roark gives a big speechy speech (cue the swell in music) about his philosophy and gets acquitted. If you've studied the law at all the trial won't make much sense. But it's a metaphor, man. Moving on!
Gail Wynand tries to back up his buddy Roark with his paper but Toohey sabotages him and Wynand shuts down his paper. He also grants Dominique a divorce when he learns that she really loves Roark. In the end (early 1940s for those keeping track), Roark and Dominique are married and Roark is working on a new skyscraper for Wynand.