The following version of this book was used to create this study guide: Butler, Halle. Jillian. Chicago: Curbside Splendor Publishing, 2015.

The novel opens in a doctor’s office. Two women—Megan and Jillian—work as administrative assistants there. Megan is 24 years old and has a generally dour disposition. She finds Jillian very irritating. Jillian is 35 years old, and she is a single mother. Jillian’s disposition is generally quite upbeat and cheerful, although Jillian is often internally frustrated. Jillian dislikes Megan, as she senses that Megan does not like her. After work, Jillian picks up her young son, Adam, from daycare. Megan returns to the apartment where she lives with Randy, her significant other. Megan and Randy’s relationship has been in decline, due in part to Megan’s steadily increasing depression and irritability. Megan and Randy go to a party, which Megan does not enjoy. Megan finds the happiness and sociability of the other guests irritating.

It soon becomes evident to the reader that Jillian’s main flaw is a lack of personal responsibility, despite her optimism and good intentions. She is forgetful and disorganized, and she often employs lies in an attempt to cover up her failures. Megan dislikes Jillian’s habitual lies. Megan continues to be bored at work and irritable at parties. Amanda—a friend of Megan and Randy—brusquely tells Megan that she needs to address her mental health issues or risk alienating all of her friends. Meanwhile, Jillian decides to adopt a dog, despite the fact that she is already raising a child on her own and does not have much time or money to spare.

Following the adoption of the dog, Jillian’s life becomes increasingly difficult. Due to a long-unpaid traffic fine, Jillian’s license is suspended, and her car is repossessed. Jillian must then rely on her neighbor, Elena, to drive Adam to daycare each day. Elena views herself as superior to Jillian and Elena makes only a cursory effort at hiding her disdain for Jillian. At work, Jillian lies that her car was damaged after Jillian hit a deer. Jillian is prescribed prescription painkillers for the car accident she supposedly endured. Jillian begins to believe her own lie, and she also begins to abuse the painkillers. Meanwhile, Megan continues to sink further into depression, irritability, and self-hatred. She dislikes herself and her life, but she feels no motivation to make any significant changes in her life.

Jillian receives a court date for her traffic fine. Prior to the court date, Jillian’s limited personal funds run out. The narration reveals that Jillian originally became pregnant from Adam after a one-night stand. Jillian calls Adam’s father to ask for money, but the father replies that he does not want to give her money, nor does he want to be involved in Jillian and Adam’s lives. Megan takes brief pleasure in Jillian’s hardships, but the pleasure is fleeting and is soon replaced by Megan’s increasingly typical bad mood. Jillian demands that her neighbor, Elena, giver her money as recompense for Elena’s haughty attitude towards Jillian. Elena’s refuses, so Jillian says that she will pray to God to punish Elena.

Megan and Randy go to another party, although Megan’s mental health is at its lowest point yet. At the party, Megan interacts with a guest named Anthea. Anthea does not seem to mind Megan’s irritable mood, and she even seems to find it refreshing. Following this interaction, Megan has a polite and mutually pleasant interaction with another guest. In the novel’s final scene, Megan waits at a bus stop on her way to work. She witnesses an interaction between two strangers, in which one stranger lets the other borrow his phone. The strangers share a moment of mutual kindness and understanding.