Jacques Richard’s new doc about the world-famous, titular Parisian programmer-archivist is actually a memoir of a lost kingdom—where a theater manager could be so influential in his priorities and choices that he’d fuel twin revolutions in film criticism (auteurism) and filmmaking (le Nouvelle Vague). Where that same avuncular gadfly would frequent TV talk shows (!) and would eventually win an honorary Oscar—for showing films, in France. Where a heated protest and riot caused by his political ejection from the institution he created was led by François Truffaut, Claude Chabrol, Alain Resnais, and Jean-Luc Godard, who was one of many clubbed by police. Where said violent confrontation actually succeeded in putting the rotund cinephile back at the prow of his ship. Godard puts it best up front: Langlois was like “a producer who ‘produced’ a way of seeing films.” While the astonishing street footage of “l’affaire Langlois”—perhaps more familiar to the French than to us—is where this exhaustive talking-heads portrait becomes beautifully, bafflingly surreal, the whole project, however conventional, has the allure of a communal embrace, a home movie of a motherland left irrevocably in the past.