Historical docudramas are hardly a theatrical genre in vogue these days especially one about an 1889 flood that few people today know or care much about. But Rebecca Gilman (Boy Gets Girl, Spinning into Butter) approaches it from an offbeat angle: focusing on a traveling family theater troupe caught in the doomed Pennsylvania town on the day of the disaster. Gilman sees the tragedy as a parable of class divisions (the working-class lowlands were deluged by the bursting of a dam built to create a fishing lake for a posh country club in the hills above) but also fashions a harrowing, up-close drama of people in crisis.