This essay approaches the US cinema of the 1920s from the vantage point of the film serial, exploring the contexts of production, exhibition, distribution and reception that are specific to this format during the decade. As a consequence, it foregrounds how the film serial differs markedly in style and language from the contemporaneous feature films. Both film serials and feature films take up the decade’s discourses of efficiency, seriality and mass culture – but they do so in radically different ways. Focusing specifically on the serial Officer 444 (Francis Ford, 1926), the paper charts how serial structures of production and narration are put to use to enact mass actions on the screen and to fashion mass audiences through this enactment, preparing them for the challenges of modernity along the way.