Each year, 60,000 people from around the globe gather in a dusty windswept Nevada desert to build a temporary city, collaborating on large-scale art and partying for a week before burning a giant effigy in a ritual frenzy.Rooted in principles of self-expression, self-reliance and community effort, Burning Man has grown famous for stirring ordinary people to shed their nine-to-five existence and act on their dreams.Spark takes us behind the curtain with Burning Man organizers and participants, revealing a year of unprecedented challenges and growth.When ideals of a new world based on freedom and inclusion collide with realities of the "default world," we wonder which dreams can survive.