Aza Holmes has trouble controlling her thoughts. She spirals into patterns of self destruction that are totally out of her control. In fact, she has a tendency to believe that her internal microbial environment holds the reins in her life. When her childhood friend Davis’ billionaire father goes missing, Aza begins new relationships and works to navigate her own mind so that she’ll be able to help others.

John Green handles the mental illness component of this novel skillfully, creating an interesting, and often difficult, reading experience that does not diminish Aza’s personhood in any way. Other aspects of the novel, however, miss the mark a bit: Davis’ poetic journal entries come across as over the top, whereas the tuatara element of the story remains peripheral when it could have been brought into focus. Actually, there are many elements of the story that feel thrown together, occupying the periphery while Aza’s mental struggle takes center stage. Perhaps there’s just too much going on here—for a largely philosophical novel, there are a whole lot of plot points that detract from the primary mental illness narrative. I can’t help but wish that Green had spent some more time paring down the story to its bare essentials.