Sara Mearns' career is the stuff dreams are made of: She's a principal at New York City Ballet, working on a piece with Broadway's Joshua Bergasse, doing fashion films with Ryan Heffington and now is featured in a short film by Ezra Hurwitz. "In a Day's Work" opens with a shot of a pretty ballerina ornament hanging from the lights of a dressing room mirror, then cuts to a close-up of Mearns wiping away her stage makeup. The back and forth between glamour and grit is a pattern that characterizes the entire film. It is a true inside look at not just the day of a dancer, but the lifetime of dedication and focus it takes to succeed. Mearns narrates her journey from the back of the class in South Carolina to center stage as an NYCB principal as Hurwitz follows her from coffee at home, to class at Steps on Broadway, to her dressing room before performance.