When Alex spies a mule chomping on greens in a nearby garden, he can't help but ask about it. "Ol' Belle?" says Miz Pettway. "She can have all the collards she wants. She's earned it." And so begins the tale of an ordinary mule in Gee's Bend, Alabama, that played a singular part in the civil rights movement of the 1960s. When African-Americans in a poor community -- inspired by a visit from Dr. Martin Luther King Jr. -- defied local authorities who were trying to stop them from registering to vote, many got around a long, imposed detour on mule-drawn wagons. As Alex looks into the eyes of gentle Belle, he begins to understand a significant time in history in a very personal way.