An instant #1 New York Times bestseller!  An instant USA Today and Wall Street Journal bestseller! The newest picture book from the creators of Iggy Peck, Architect; Rosie Revere, Engineer; and Ada Twist, Scientist stars Sofia Valdez, a community leader who stands up for what she believes in!   Every morning, Abuelo walks Sofia to school . . . until one day, when Abuelo hurts his ankle at a local landfill and he can no longer do so. Sofia (aka Sofi) misses her Abuelo and wond