If movies are our kiss-kiss-bang-bang arenas of desire, then this addictive movie-centric documentary from Paul Mariano and Kurt Norton makes the Library of Congress sound like the Playboy Mansion. These Amazing Shadows celebrates the LOC's National Film Registry, which selects 25 American films per year as candidates for preservation (550 to date, from Abbott and Costello Meet Frankenstein to Zapruder Film). Since inclusion doesn't guarantee preservation, and celluloid is fragile, the filmmakers have a three-pronged intent: to seduce (with clips from movies you love, and others you'll want to seek out), to educate (via interviews with scholars, directors, and mad-scientist-like archivists), and to sound a call to action to preserve both Hollywood product and "orphan" works, a category that includes amateur, experimental, and industrial films. And their documentary spotlights not only the feel-good stuff but also "the lies we tell ourselves" — Birth of a Nation being the most notorious example.