Caitlin remembers a childhood memory in which Cass hit her with a shovel while they played at a park. The incident gave Caitlin a scar above her eyebrow and the two sisters share the scar as “one more thing [they] had in common” (10). Caitlin describes Cass’s early life and how Boo suggested the name Cassandra, who is a seer. Caitlin is named for Boo, whose real name is Katherine, the Irish variation of which is Caitlin.

Caitlin describes her sister, who was impressive when she was in high school: student body president, volunteer in the community, soccer star, Homecoming Queen, and excellent student. When Cass got into Yale, the whole family was happy, but it marked the start of Cass’s negative feelings and erupted in her running away.

Caitlin’s 16th birthday, the day that Cass leaves, is a chaotic event, and most of the hours are spent calling different places to try to figure out where Cass went. Caitlin remembers the start of Cass and Adam’s relationship, and how confused Caitlin felt about why someone would feel so infatuated with another person. As Caitlin remembers Cass, she reflects on how her own accomplishments pale in the face of Cass’s.