Streep has shown a particular weakness for playing gorgons lately, and Shanley’s screen version of his 2005 Tony-winning play allows her to inhabit a doozy. Her Sister Aloysius is indisputably the moral authority of the Bronx’s St. Nicholas school, hovering like a black-bonneted bird of prey. So when another nun suggests that they may have a predator in their midst (Hoffman), the sister starts sharpening her talons. Credit Streep for keeping the fires raging; the fact that her performance stops the film from becoming another trapped-in-amber adaptation is beyond a shadow of a you-know-what. Meanwhile, Viola Davis steals the show with her single scene. Extras include a number of conversations with cast and crew—notably one with composer Howard Shore, whose work here with Shanley seems especially collaborative.