I Am Divine riffs entertainingly through the career of the drag star who blazed in Pink Flamingoes and Hairspray. Harris Glenn Milstead (so born) appalled his Baltimore parents – later reconciled to junior’s fame and notoriety – by coming out, cross-dressing, going to California . . . It got worse and worse. Divine and director John Waters, best interviewee in Jeffrey Schwarz’s documentary, were soon tabloid headliners with their trash-meets-tinsel, scandal-courting movies. Cabaret followed; chat shows. The rest, until Divine’s death in 1988, was showbiz history, a unique and still unrivalled mixture of the sweet and the shocking.