Book-It Repertory Theatre, which adapts novels for the stage, has thrown a few air balls over the years—but it has bookended this, its 20th season, with marvels. Up now is a remount of the first half of its 1996 hit The Cider House Rules, derived from John Irving's story of a Maine orphanage in the 1930s. At its center are the ether-addicted doctor who delivers the babies (and performs clandestine abortions) and an openhearted innocent named Homer Wells who can't find a family. The play hits all the notes—sweet, sad, funny—and Peter Crook's performance as the conflicted doctor is a masterpiece of control and modulation. (Center House Theatre, Seattle Center, 216-0833. 7:30 pm, $15–$30.)