Mercy is the protagonist of Chapter 3, which begins on September 6, 1970. Robin and Mercy drive David to Pennsylvania for his freshman year at Islington College. On the return trip, Robin says, “I suppose we should go out and kick up our heels tonight, now that we’re back to just the two of us. Go out for a fancy meal or, I don’t know, have wild sex on the living-room floor or something” (62). David’s absence is especially difficult for Mercy because she feels closer to him than she is to Alice, who is bossy and overconfident, or Lily, who is portrayed as “emotional.”

Mercy also feels joyful anticipation as she puts a secret plan into action. The following day, Labor Day, when Robin goes to work, Mercy places her favorite clothes in a box and carries them several blocks to her art studio, situated above a garage. The room has a tiny bathroom, a kitchen area, a table and chair, and a daybed. As she dreams about the studio, she experiences “a kind of inner leap at this thought, a sense of enthusiasm she [hasn’t] felt in years” (65).