This chapter discusses anachronism as a form of metalepsis and different ways of understanding anachronism in the ancient and modern worlds. The chapter begins by highlighting potential complexities in applying Genette’s model of metalepsis to ancient literature, drawing out the differences between the case of a character about to murder a reader in Cortázar’s ‘Continuity of Parks’ (discussed by Genette) and that of a character, Helen, blinding and then healing an author in Stesichorus’ Palinode. It then turns to anachronism, a phenomenon which renders synchronous things that, from a historical/chronological perspective, do not belong to a shared temporal plane, and can thus be understood as metaleptic when the time periods involved are ‘the world in which one tells’ (the present) and ‘the world of which one tells’ (often, in the ancient world, the remote heroic past). The chapter moves from a modern instance which highlights anachronism’s pointedly transgressive potential (the use of 1970s music in Brian Helgeland’s 1370s-set movie, A Knight’s Tale) to the dominant ancient discourse about anachronism, according to which most anachronism is inadvertent and the critic’s job is to correct it. But the chapter argues that despite this, ancient sources such as Plato’s Symposium do recognize a more artful use of anachronism and potential modes of audience response to it, and concludes by asking what a pointedly erudite astronomical anachronism in a poem of Theocritus tells us about the audience envisaged by its author.