Most good stories start with a fundamental list of ingredients: the initial situation, conflict, complication, climax, suspense, denouement, and conclusion. Great writers sometimes shake up the recipe and add some spice.
Initial Situation
Aging author Nathan Zuckerman learns that his childhood idol Seymour "The Swede" Levov (dead from cancer two years before) has a daughter (who might be dead, too) that bombed a post office to protest the Vietnam War.
Zuckerman takes the few clues that he has and writes a book imagining the Swede's life with his daughter, before and after the bombing. The following stages of the plot analyze that story. Because the Swede's story weaves in and out of time, sometimes there is more than one time period involved in a particular stage.
Conflict
In imagining the Swede's story, Zuckerman assumes that the Swede blames himself for Merry's actions. So, he imagines things the Swede might have done that make him feel guilty. These include Merry asking him "kiss me the way you k-k-kiss umummother" (3.123), and him going along with her request—which, of course, makes things weird between them.
Then when Merry is sixteen, she starts protesting the Vietnam War. The conflict stage ends with information we already know—that Merry, in an act of political protest, has bombed the post office, killing a local doctor.
Complication
Soon after Merry disappears, Rita Cohen approaches the Swede and says she knows Merry… and knows where she is. She asks the Swede to give her some of Merry's things, a bunch of money, and to have sex with her. He does give her money, but doesn't have sex with her.
After that, Rita disappears and the Swede spends the next five years not knowing where his daughter is. To further complicate matters, the Swede's wife Dawn is suicidal and is hospitalized several times for psychological issues she's facing as a result of her daughter's actions and disappearance.
Climax
The visit to Merry is the big emotional climax for the Swede. He finally sees his daughter again after five years, but he's horrified at what she's been doing and what she's become. He learns that she is in fact the Rimrock bomber and that she's killed three people in addition to the doctor. She's been raped several times and has lost teeth.
She's living as a Jain and has taken vows of nonviolence and poverty. After hearing her story and having a very hard time with it, the Swede, appalled by the smell of her breath, vomits in her face.
Suspense
Now the Swede is in a quandary. He still loves his daughter, but he doesn't know how to help her. He can't just leave her the way she is. But he feels that taking any action would either violate her rights or alert the authorities and put her in jail.
Much of the suspense happens after the denouement, after the Swede learns of Dawn's affair, when he's trying to decide what to do. Break Orcutt's face? Run away with Sheila to Puerto Rico? Go get Merry? Take Sheila to go talk to Merry? Run away with Merry to Puerto Rico?
Denouement
"Denouement" is a French word that literally means "unraveling," specifically "the final unraveling of the complications of a plot in a drama, novel, etc" (OED Online). When the Swede sees Dawn and Bill Orcutt having sex in the kitchen, there are few things left to be revealed. We learn the Swede, too, had an affair, a very short one with Merry's speech therapist, Sheila, who is there at the dinner party.
The story has come undone, but there are still a few surprises left.
Conclusion
We aren't sure how conclusive this conclusion is. The Swede hears his father scream. He imagines that Merry is here, that she's confessed to Lou, and Lou died from the shock. He walks into the kitchen and learns that his father is screaming because Jessie Orcutt (the drunk wife of Bill) has stabbed him in the face.
And: boom. That's the novel's final scene. Check out "What's Up With the Ending?" for a discussion of this seemingly inconclusive conclusion.