In Chapter 6, after Helios announces Circe's exile, no one speaks in her defense or even looks at her. She uses a simile and situational irony to comment on how it feels to be ignored in this moment:
For the last time, I watched all the gods and nymphs take their places. I felt dazed. I should say goodbye, I kept thinking. But my cousins flowed away from me like water around a rock. I heard their sneering whispers as they passed. I found myself missing Scylla. At least she would have dared to speak to my face.
The idea that Circe's family moves around her "like water around a rock" draws attention to how Circe is already stranded on an island in her father's house, long before her exile. Her family wants nothing to do with her and is perfectly content to ignore her even when she is right in front of them. Eventually, on Aiaia, Circe will create magical shields to keep most gods and mortals at bay. Because of her defenses, she appears in many myths and stories as a bitter isolationist who is not to be trusted. This passage suggests that in a figurative sense, these barriers were put in place by her family long before she became a powerful sorceress; unable to break them down, Circe learns to turn them against others as a shield.
The simile also evokes Scylla's lonely fate, stranded in a rocky ocean cave and hoping for sailors to drift near enough for her to eat them. Circe, who has always hated Scylla, is responsible for this fate: hoping to get the coquettish nymph out of the way so that Glaucos might fall in love with her, Circe cursed Scylla to an immortal life of monstrosity and isolation. However, the curse transforms not only Scylla but also Circe into an irredeemable monster in their family's eyes. Circe's yearning for Scylla in this moment highlights the irony of the situation. Whereas Circe once thought of Scylla as the one person keeping her from a life of connection and love, the curse turns Scylla and Circe into the only people who might be able to understand one another. In an even more tragic twist of irony, Circe's curse has rendered Scylla senseless. The two women are bound together but will never be able to speak to one another again, even in anger.
In Chapter 7, Circe arrives on Aiaia for her eternal exile. After a fearful first night, a simile helps her arrive at an epiphany about the irony of her situation:
The worst of my cowardice had been sweated out. In its place was a giddy spark. I will not be like a bird bred in a cage, I thought, too dull to fly even when the door stands open.
I stepped into those woods and my life began.
Circe has been miserable her whole life because of the social norms and expectations into which she was "bred," like a bird. For all beings but especially for an unloved nymph like her, her father's opulent and hierarchical house is essentially a gilded cage that limits her to a narrow role propping up the most powerful gods. When Circe admitted to witchcraft, she introduced the idea that a nymph could have power unavailable to "higher" gods. She thus threatened the entire structure, rattling the bars of the cage. Helios and Zeus have exiled Circe to protect their beloved cage.
Circe realizes that if she hides in the house for the rest of her life, she will be "caging" herself. She does not want to be like a bird that stays in its cage out of habit, even when offered freedom. Her resolve to seize the opportunity before her helps her see the irony of her exile. What is intended as a punishment—a more secure cage—turns out to be anything but. Finally free of her father's court, Circe can make whatever she wants of herself. She has an entire island to make her own. As the novel goes on, she does struggle with loneliness and confinement from the rest of the world. However, she is able to build her own community and leverage her exile to make a path for herself that would have been unimaginable inside the "cage."
At the start of Chapter 17, Circe comments on the situational irony of Odysseus's restless sleeping patterns. Little does she know that this irony foreshadows what is to come in this chapter:
For most men [sleep is] a reminder of the stillness that waits at the end of days. But Odysseus’ slumber was like his life, tossed and restless, heavy with murmurs that made my wolves prick up their ears. I watched him in the pearl-gray light of dawn: the tremors of his face, the striving tension in his shoulders. He twisted the sheets as if they were opponents he tried to throw in a wrestling match. A year of peaceful days he had stayed with me, and still every night he went to war.
As Circe notes, poetic comparisons between sleep and death are common. Falling asleep is the only living human experience that people imagine might be similar to dying. Consequently, many people think euphemistically of death as the ultimate rest at the end of one long day, life. Circe reverses this metaphor: sleep ought to be as quiet and restful as death if only for a while. Odysseus has every reason to sleep peacefully, having spent a year in the comfort and safety of Circe's home. Still, Circe claims, "every night he went to war." His sleep imitates his noisy life, not his quiet death.
At first, it seems as though Circe may simply be charmed by Odysseus's restless sleep. It is one of the unexpected things about him that makes him interesting to her. However, his restlessness also foreshadows his next adventure. Immediately after this passage, Apollo delivers a prophecy that Odysseus must travel through the underworld before he can go home. This is not typically something a mortal would do in the course of their life. Most go to the underworld only when they die, and they remain there. However, Odysseus makes his journey right away and returns within the course of the chapter. "Dying" and refusing to stay put in the underworld thus becomes another one of his heroic feats. In a way, his sleep does mimic this first, restless death of his after all.
In Chapter 20, after Circe proves that she would be willing to endure eternal pain in exchange for Trygon's tail, he offers it to her freely. The moment when she cuts it, far more easily than she would have expected, is rife with imagery and situational irony:
The tail came free in my hand. It was nearly weightless, and up close there was a quality to it almost like iridescence. “Thank you,” I said, but my voice was air.
I felt the currents move. The grains of sand whispered against each other. His wings were lifting. The darkness around us shimmered with clouds of his gilded blood. Beneath my feet were the bones of a thousand years. I thought: I cannot bear this world a moment longer.
Then, child, make another.
He glided off into the dark, trailing a ribbon of gold behind him.
Once Trygon has agreed to give Circe his tail, she is the one who begins hesitating. To cut the body of this immensely powerful creature, inflicting on him an eternity of pain, seems both unnatural and antithetical to Circe's values. She desperately wants to break free of the cycle of violence into which she was born. Cutting Trygon's tail is not an act of self-defense, as killing violent men is. Circe will not be able to take this decision back.
When she finally does cut the tail, she is struck not by how difficult it is to slice through, but rather by how easily it comes away with only a little pressure from her knife. All of the imagery of the passage is lighter and more beautiful than Circe expects it to be. The tail should be the heaviest thing Circe has ever held in her hand, but instead it is "nearly weightless." Instead of gory and horrifying, the detached tail looks "iridescent," like some pearl she has merely picked up off the ocean floor. The sand "whispers" instead of screaming, as witnesses to this crime ought to do. Trygon's golden blood even makes the water "shimmer," lighting it up instead of darkening it like blood usually would. Taking Trygon's tail turns out to be far easier and more anticlimactic than Circe ever could have suspected.
Still, Circe knows that she has hurt Trygon for her own gain. This knowledge in itself would be overwhelming, but she nearly buckles under the tension between the horror she feels within and the quiet beauty all around her. It makes her think about the "bones of a thousand years" that she walks on every day without noticing, the accumulated bodies that have piled up in the wake of her and other gods' violent quests for power. Trygon leaves Circe with a simple reminder of her own agency: if she cannot stand the world she lives in, it is up to her to "make another" in which sacrifices are honored and violence is not such a casual part of life that it goes unnoticed.