Every morning, Abuelo walks Sofia to school...until the day that Abuelo hurts his ankle at a local landfill and he can no longer do so. Sofia misses her Abuelo and wonders what she can do about the dangerous Mount Trashmore. Then she gets an idea--the town can turn the slimy mess into a park! She brainstorms and plans and finally works up the courage to go to City Hall--only to be told by a clerk that she can't build a park because she's just a kid! Sofia is down but not out, and she sets out to prove what one kid can do.