This article bridges a gap in the study of Aristophanic humour by better demonstrating how individual jokes (in this case, the para prosdokian ‘contrary to expectation’ joke) contribute to the wider comic scenes in which they are embedded. After analysing ancient and modern explanations and examples of para prosdokian jokes, this paper introduces the concept of ‘comic bit’, a discrete unit of comedy that builds humour around a central premise, and establishes how para prosdokian jokes contribute to comic bits in a way that recent theories of para prosdokian cannot account for.