But you shall not escape my iambics.

The line is a pointed warning that the speaker’s weapon will be verse: “iambics” evokes the iambic tradition of invective (associated with Archilochus and later Roman satiric abuse), in which poetry is used to shame, expose, or punish an opponent. In Catullus’s world, literary skill is not merely ornamental but socially consequential—poems circulate among elites and can damage reputations. The threat also underscores the poet’s confidence in the efficacy of his art: even if the target evades other forms of retaliation, they cannot evade being fixed in biting meter and remembered through circulation and posterity.