In "Mistress America", Tracy (Lola Kirke) is a lonely college freshman in New York, having neither the exciting university experience nor the glamorous metropolitan lifestyle she envisioned. But when she is taken in by her soon-to-be stepsister, Brooke (Greta Gerwig) - a resident of Times Square and adventurous gal about town - she is rescued from her disappointment and seduced by Brooke's alluringly mad schemes.