If you attend The Green Room's current production of Angels in America: Perestroika, I assume you know that you'll be entering playwright Tony Kushner's work halfway through, as part one of this two-part saga, Millennium Approaches, debuted at the Rock Island venue on Halloween. The back page of Perestroika's program provides a very bare-bones summary (or refresher) on what previously occurred in Kushner's epic exploration of the 1980s, but, I'll venture, your enjoyment of this second outing will be significantly enhanced by familiarity with the show - and not just familiarity with the Green Room's first installment.