They don’t call Mary Rochelle Douleur “Roach” for nothing — she’s practically indestructible. With a disease that makes her unable to feel physical pain, Roach can fall down stairs, stick her fingers in electrical sockets, or scratch her eyeballs and still look up with a smile. But when she and her older sister Mary May become rival stand-up comediennes, they learn just how fine the line is between laughing and crying.