A bomb goes off in a Greenwich Village townhouse, killing three members of the militant Weather Underground. Afraid of being arrested, several of their comrades go on the run. The year is 1970. In his life and in his writing, 26-year-old playwright Zayd Dohrn is a connection between these two powerful moments in American political history. Dohrn, a graduate of Boston University's playwriting program, captures the former in "Haymarket," his drama now getting a workshop production at the Boston Playwrights' Theatre. The latter comes from his own life: Dohrn's parents, Bernardine Dohrn and Bill Ayers, were two of the Weathermen...