Variable—Third Person Limited Omniscient/Third Person Universal/First Person (Briony Tallis)
Atonement is a sneaky ninja book. It has a complicated narrative point of view, which means it's not always clear who is speaking, or where they're coming from. And yes, Briony Tallis is the secret point of view ninja.
Stealth Third Person, With Knives
Most of the book is in third person. The final part, however, is in first person as told by Briony. In the last part, Briony reveals that the whole book is actually written by her. So everything you read in the book is actually being said by Briony, even though it's in third person.
And, as she also confesses in the last section, sometimes she lies. We guess ninjas aren't necessarily the most reliable narrators.
One of the ways Briony-the-writer lies is that she tells you what other people are thinking, though, of course, she couldn't possibly know for sure. Again, the bulk of the book is in third person… but generally it's in third person limited omniscient, which means that we're usually riding along in one particular person's head. Who this person is, though, switches around.
Even More Minds
A couple of times, we end up in Emily Tallis's head (see 1.6), laying in bed with her as she thinks her way out to the rest of the house and considers what is happening there. We're not actually with Emily, though, since Briony wrote the book, so what we're actually privy to is Briony's understanding of Emily's drifting dream of everyone else. Yeesh.
And sometimes—as in part 3, or much of part 1—we're in Briony's head. And you'd think that Briony the old writer would at least know what Briony the child or Briony the young woman thought, but Briony the old writer has already admitted to lying, so all bets are off.
Finally, there are a couple of points in the novel that switch from third-person omniscient to third-person universal. In these sections, the narrator seems to know everything, and often leaps ahead in time to tell you about it.
This happens, for example, in the third paragraph of the novel. Briony's mother has just read The Trials of Arabella, and the narrative tells us, "Briony was hardly to know it then, but this was the project's highest point of fulfillment. Nothing came near it for satisfaction, all else was dreams and frustration." At first, this seems like a universal narrator, speaking from we-don't-know-where. Later on, when we reach the last part of the novel, we realize that this is Briony, the elder, looking back and telling us what happened to her.
But… we also, at the end of the novel, see the triumphant final performance of The Trials of Arabella, which occurs after Briony (in the novel) finished her text of Atonement. So the universal narrator here is actually, as it turns out, wrong. Which just goes to show you can't trust anyone.
Why all these puzzle box narrators within narrators, with various consciousnesses popping out at you like ninja-jack-in-the-boxes, all sneaky and bouncy and confused? Well, part of the reason seems to be that Briony is fascinated with seeing into other people's minds. "She need only show separate minds, as alive as her own, struggling with the idea that other minds were equally alive" (1.3.24), she muses excitedly at one point. As a child, and later as an author, she loves trying to figure out what other people are thinking. So, naturally enough, her book is filled with her trying to figure out what other people are thinking.
The other reason for the point of view ninjaness, though, is that Atonement is (as we've also mentioned in the "Symbols" section) self-referential. It's about itself, and about the process of imagining and creating novels. So you get imaginings within imaginings, minds making minds making minds.
In the end, Briony seems to feel that she's failed—no matter how many minds she makes, they're all in her mind after all. "[A] novelist… is also God," she says sadly. "There is nothing outside her. In her imagination, she has set the limits and the terms" (4.46). But has she? Who is writing those words? Briony? But she's a character too. Who's writing about her? And, for that matter, who's writing about you? At the end of Atonement, we sort of end up looking over our shoulders to try to figure out which ninja, or God, has us in its point of view.