Randy Newman once sang, "I'll talk to strangers if I want to, 'cause I'm a stranger too." Pondering whether the madness that drives families, friends and lovers apart is really greater than the madness that holds them together, Black Clock 19 is full of mad strangers: the one in the neighborhood in Susan Straight's "Closing the Gate," the one in the house in Janet Sternburg's "White Matter," the one bringing a message in Joseph McElroy's "Plea."