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.
Exposition (Initial Situation)
Water, Water Everywhere
When the story begins, an unnamed narrator is bringing her boyfriend and another couple to the region of Quebec where she grew up. The purpose of the trip is to try to find her father, who has apparently disappeared. Together, the quartet travels out to the island in the middle of a lake where her parents had had a cabin. In this remote and isolated location, things are going to get pretty cozy pretty quickly…
Rising Action (Conflict, Complication)
Not A Father To Be Found
When they get there, they find that her father still hasn't turned up. The narrator is unsure of what to do next. In fact, she seems unsure about a lot of stuff—her relationships with her boyfriend and other friends are a big example. She wavers between thinking her father is dead and, after finding some drawings he did, believing that he might have gone crazy. She eventually realizes that the crazy sketches are actually tracings of rock drawings. So, she goes back to the theory that he's probably dead. Still, she decides it would be worthwhile to hunt down the actual rock drawings and confirm her theory that her father had been pursuing them as well.
Meanwhile, she and her boyfriend, Joe, are fighting because the narrator doesn't want to marry him, and David and Anna (the other couple) are also having drama. David flies his "jerk" flag pretty proudly; his favorite hobbies on the trip seem to include humiliating Anna and making unwelcome sexual advances toward the narrator (his less favorite hobbies include fishing and talking about how much he hates Americans). In short: relations within and between the couples get a little… difficult.
Climax (Crisis, Turning Point)
Between A Rock And A Hard (Possibly Hallucinogenic) Place
Trying to ignore all the crazy romance drama and focus on finding out what happened to her dad, the narrator goes out searching for one of the paintings, which she believes is located on the face of a cliff (submerged under water).
While she's diving down in the lake to try to see the painting, she believes she spies a kind of fish-like figure below, and the moment sparks an epiphany for her—and for the reader. Although it's never really quite clear what she "actually" saw down there, it makes her realize that some of the memories she's been indulging in throughout the trip (and relaying to the reader, of course) aren't exactly accurate. She tells the reader that the figure she sees swimming below her is the fetus of a baby she aborted some time ago. Previously, she had told us about an ex-husband and the child she left with him, but now we learn those memories were inaccurate; instead, they were fictions she had built up in her mind to protect herself from bad memories.
Once she's back on dry land, she comes to the conclusion that her father wasn't just tracking existing rock paintings; he was also finding new places that had spiritual power—that is, new sacred spots.
Falling Action
Let's Make Like the Animals And Hide
With her newfound knowledge and apparent connection to the spiritual world in hand, the narrator is not ready to leave the island cabin just yet. So, she hides from the others on the day that they were supposed to scoot. When they leave, she comes back out. At this point, her new mission appears to be to connect with the spirits of her deceased parents. (Oh yeah, we skipped over that part—Paul had come by the previous day to say they had found her father's body.)
To make that happen, she engages in a lot of ritualistic behavior in an apparent attempt to bring herself into harmony with the natural (i.e., non-human) world, stripping off her clothes and even making a lair for herself like an animal. She also goes on a tear, destroying all the clothes and other objects in the house. Eventually, she gets her wish and reports seeing both her mother and her father.
Resolution (Denouement)
Return to the City?
Having seen her parents, the narrator seems resigned to returning to the "real" world. While she's back inside getting dressed in her ripped clothes, Joe and Paul arrive. Joe calls out for her, and the narrator lets drop that she now knows she loves Joe and thinks she can trust him. We're not sure what happens from there, though, since Atwood leaves us with a… cliffhanger.