It's sizzling in Sunny Phoenix, Arizona. Hannah and Steve have money for plane fare to join the rest of the family in up-state New York. However, remembering a classmate's label of the family's 1967 Ranchero hydrogen conversion car as a "heap of junk," Hannah convinces her sister of a new plan to prove him wrong. They will drive the old car across the country, an alternative fuel adventure which involves the family pets: a hilariously rude parrot named Sam and the faithful dog, Scooter. What unfolds is a story of colorful characters with challenging and sometimes dangerous circumstances. The sisters' wit and courage are tested, creating a bond they never expected during a summer they would never forget.