An instant New York Times bestseller!"A deeply satisfying, page-turning, genre-defying read." --Kirkus Reviews (starred review) Since Grandpa died, Dally's days are dull and restricted. She's eleven and a half years old, and her exacting single mother is already preparing her to take over the family business. Starved for adventure and release, Dally rescues a mysterious envelope from her mother's clutches, an envelope Grandpa had earmarked for her. The map she finds inside leads straight to an ancient vault, a library of secrets where each book is a portal to a precise moment in time. As Dally "checks out" adventure after adventure--including an exhilarating outing with pirates--she begins to dive deep into her family's hidden history. Soon she's visiting every day to escape the demands of the present. But the library has secrets of its own, intentions that would shape her life as surely as her mother's meticulous plans. What will Dally choose? Equal parts mystery and adventure--with a biracial child puzzling out her identity alongside the legacy of the past--this masterful middle-grade fantasy rivets with crackling prose, playful plot twists, and timeless themes. A satisfying choice for fans of Kindred and When You Reach Me.