The novel is contemplative and self-reflective. Within this framework, the mood varies according to how Circe feels about her life. There is constantly the sense that Circe wants to be a better version of herself. She goes through periods of growth as well as plenty of setbacks, mirroring for the reader the joy and frustration of healing and self-improvement.
At times, the novel is also suspenseful. In addition to her role as the protagonist of a psychological novel, Circe is also a character in Greek mythology. This creates moments in which the reader knows more than Circe by virtue of familiarity with some of the stories she is living through. For instance, when Circe meets Icarus, the reader may already know how the boy will die. A cloud of suspense hovers over the rest of Circe's stay on Crete. It only resolves at the end of the chapter, when she discusses what became of Daedalus and Icarus after she left. The moment when the suspense pays off is bittersweet: it is at once satisfying for the reader to be right and also devastating to see mythological heroes rendered as real people whose lives have ended in the tragedy for which they were always destined.
Circe's retrospective narration creates its own moments of suspense. For example, in Chapter 12, Hermes tells Circe about a horrible act of revenge Pasiphaë wrought on all the women her husband slept with:
I felt a weightless joy. The story was so ugly, so outlandish and disgusting, that it felt like a fever breaking. If I was trapped on this island, at least I did not have to share the world with [Pasiphaë] and all her kind. Pacing by my lion, I said, “It is done. I will think of them no more. I cast them out and I am finished.”
The cat pressed her cheek upon her folded paws and kept her eyes upon the floor. So perhaps she knew what I did not.
The reader shares in Circe's disgust but also her relief that she is safe from the rest of the world—that is, until the narrator version of Circe lets on that her past self was naive. In the very next chapter, she begins to receive a series of visitors who bring all the horrors of the outside world to Aiaia. She wonders if even the lion could see what she herself could not at the time. This moment conjures for the reader not only the feeling that something bad is about to happen, but also the feeling of helplessness that can come with hindsight. No matter what Circe knows now, she cannot reach her former self to warn her. The novel thus demonstrates that reflecting on the past with the knowledge of how it turned out can be just as suspenseful as reading a novel with prior knowledge of the myths on which it draws.