Invoking “Babylon” in the title of Julien Temple’s documentary on London seems bleak, but it’s really a dare. This is a montage spanning 100 years, from the turn of the 20th century to the 2012 Olympics. Temple splices in anachronistic images and music throughout, so that the future cuts into the past and the past is ever-present. He has a penchant for punk, a subject he’s covered before, and when Edwardian-era suffragettes smash windows to X-Ray Spex’s “Oh Bondage! Up Yours!” it’s not the first or last time the movie feels like one long music video, something else Temple’s spent time on. T.S. Eliot and William Blake have their say, and a pigeon-capturing lady on the streets gets more screen time than Lady Diana. But this is no crazy quilt. Temple and editor Caroline Richards demonstrate that the London mob (it can seem like there’s been only one mob through the ages) time and again rescues the city from its complacency—and safeguards it from the suffocation of class-bound England. Temple never shirks from the city’s racism, poverty, or unfair policies. Ordinary people, old ones with long memories, and icons like Malcolm McLaren testify to London’s elusive redemption. But Temple doesn’t seem to believe that angry angels will fell this place. Rather, salvation will come from the flowers in the dustbin, and London will thrive as long as its downtrodden can shake a fist.