Director Craig Zobel (Compliance) and screenwriter Nissar Modi (Breaking at the Edge) transform Robert C. O’Brien’s post-apocalyptic science-fiction tale into an intimate story of cautious rebirth with a highly charged ménage á trois that everyone knows cannot maintain and bear meaningful fruit for humanity. Ann Burden (Margot Robbie) manages alone on her family farm until she encounters Loomis (Chiwetel Ejiofor), a serious scientific thinker who augments her rural survival skills and slips inside her emotional defenses. They forge a developing partnership until the arrival of Caleb (Chris Pine), a shrewd charmer seemingly intent on shifting the dynamic in this new Eden. The film version of Z for Zachariah feels like a psychological reworking of Genesis, infused with vitality thanks to a pitch-perfect cast that makes the heart beat faster. (Opens Friday at Esquire Theatre) (PG-13) Grade: B