Now that Truly Lovejoy's father has been injured by an IED in Afghanistan and is having trouble finding work back home, the family moves from Texas to tiny Pumpkin Falls, New Hampshire, to take over Lovejoy's Books, a struggling bookstore that's been in the family for one hundred years.

With two older brothers and two younger sisters clamoring for attention, her mother back in school, and everyone up to their eyebrows trying to keep Lovejoy's Books afloat, Truly feels more overlooked than usual. So she pours herself into uncovering the mystery of an undelivered letter she finds stuck in a valuable autographed first edition of Charlotte's Web, which subsequently goes missing from the bookshop. What's inside the envelope leads Truly and her new Pumpkin Falls friends on a madcap treasure hunt around town, chasing clues that could spell danger.