When the intrusive thoughts start, Aza feels entirely at the mercy of the thoughts and what they tell her to do. Notice that Aza pits her self against both her body and her mind. The way she sees it, no part of her is on her side. This passage shows that giving into the intrusive thoughts can bring Aza a sense of comfort and order: she can breathe easy knowing that she prevented the infection in her finger for today, though she makes it very clear that this process will repeat again and again.