Every few years since 2005, twelve Boston heroes have been surprised by phone calls from the Barr Foundation. Chosen from among hundreds of leaders of area nonprofits, these twelve receive a unique offer – to become Barr Fellows. This means a three-month sabbatical, group travel to the global south, and the opportunity to join a remarkably diverse network of leaders. The Barr Fellowship is a recognition for leaders' past accomplishments. It is also an investment in their relationships with each other - without set expectations about what would emerge as a result. There is only a guiding hypothesis that great things would emerge. In this short film, six Barr Fellows discuss, in their own words, how powerful collaborations can spring from a diverse "social capital petri dish."