The plot's the thing. It is not, of course, the only thing, for Aristotle perhaps means little more (or less) than a point about medium (that drama only comes into existence when some action happens), while Anglophone critics use the term ‘plot’ in different ways for different purposes, not all of which can automatically be said to reflect on each other. It is nonetheless possible, I suggest, to make a claim for a particular kind of plot activity as integral to the workings of Roman comedy: that internal plotting is a programmatic sign for comedy; that internal and external plotting (that is, the best laid plans of the characters in the play, and the plot of the play) are mutually reinforcing; and that instability of identity within a play slides into the precarious construction of identity in the production of a play. This means not just that there is a lot of deceit and a lot of instability of identity in Roman comedy, but specifically that these issues work together, and that they constitute a programmatic metaphor for the dramatic performance.