The novel opens with the first of 13 letters addressed to the 17-year-old protagonist, Virginia “Ginny” Blackstone, written by her Aunt Peg. Ginny lives in New Jersey with her parents. Growing up, she was close with Peg, who lived in New York City. Peg left home without a word two years prior to the start of the novel. Although this information is not revealed until Chapter 2, Peg has been dead for three months. So, Ginny is surprised when the first envelope arrives in the mail.

In this first letter, Aunt Peg includes $1,000 and asks Ginny to buy a passport, a backpack, and a one-way ticket to London. She tells Ginny that this is a game she’s designed, inspired by a game of imagination that they used to play when Ginny was a girl, which they called “today I live in…”

Aunt Peg’s letter instructs Ginny to go to the Chinese restaurant under Peg’s old apartment in New York City; there’s another envelope waiting for Ginny there. She tells Ginny to plan on traveling for several weeks and then outlines the rules for this travel game: Ginny can carry only what fits in her backpack; she is not allowed to bring any guidebooks, language aids, or a journal; she cannot bring any money (Peg says she’ll take care of that); and she is not allowed to bring a cell phone, laptop, music, or camera.