If you found Cloverfield, Hollywood’s blockbuster version of the death of a city, a lot of fun, you might want to avoid this Bill Guttentag/Dan Sturman documentary about the real thing. Relentless and restrained, it shows the true face of the beast. In 1937, the Japanese took the title city and in the weeks to follow murdered some 200,000 persons. A handful of foreign residents formed a safety zone to protect refugees. American schoolmistress Minnie Vautrin tried to shield women from the soldiers. (The rape toll is estimated at 20,000.) German Nazi John Rabe spearheaded the group and is perhaps the only person to use a swastika for humanitarian purposes. Told with horrific archival footage, harrowing personal accounts, and dramatic readings by Mariel Hemingway, Woody Harrelson, and others, Nanking confronts an evil that, 70 years later, still chills the soul. Chinese + Japanese + English | 89 minutes | Boston Common + Fenway + Fresh Pond + Circle/Chestnut Hill + suburbs