Conjoined twins Daisy and Violet Hilton were once the cream of the sideshow crop. Taught to sing and dance at an early age, the winsome duo ascended through the early 20th-century vaudeville circuit as a side attraction (working alongside Bob Hope and Charlie Chaplin as well as a memorable turn in the Tod Browning classic “Freaks”) before a cascade of unscrupulous management and harsh mistreatment brought their careers (and lives) tumbling down. This engrossing glimpse into a bygone era is filled with fascinating interviews and rare archival footage.