In John Green’s Sand Castles, comic characters try desperately to make sense of their fleeting lives. The set of three short plays makes up a tender tale about letting go, telling the truth, and believing in tomorrow. The Reunion features middle-aged fraternity brothers in a battle to convince each other their lives are a success. In The Heart Mind Dialogues, Mind does its best to calm Heart in the face of impermanence. In The Girl with the Red Umbrella, two men, caught in the rain, do their best to assure a young newlywed that her troubled marriage can work.