It may be agreed that the character of Medea, one of the most intertextual heroines of the Graeco-Roman literary tradition, is a veritable crucible of the most disparate emotions, as the articles gathered in this issue aim to show. In Seneca's Medea, readers encounter a murderous mother who kills her own children, giving in to destructive anger or, rather, fury. This emotion has been widely and extensively studied both in relation to its Greek model, Euripides’ Medea, and in the light of the Stoic view on passions, so that it can be acknowledged as one of the most salient features of the Roman character's emotional profile from a literary and philosophical standpoint. Although both Medeas, while struggling within themselves in their famous monologues, debate whether they should or should not kill their children, Euripides’ heroine does not seem to murder them out of anger: she repeatedly claims that a pressing necessity urges her to do so; by contrast, the Senecan Medea lets her anger literally lead the way (ira, qua ducis, sequor; 953). They both describe the filicide they are about to commit as a sacrificial act (compare Eur. Med. 1053‒4: ὅτῳ δὲ μὴ / θέμις παρεῖναι τοῖς ἐμοῖσι θύμασιν, ‘whoever is not permitted to attend my sacrifice’ and Sen. Med. 970‒1: uictima manes tuos / placamus ista, ‘with this victim we placate / your spirit’), but Seneca's character is pushed towards it by the dreadful hallucinations of the Furies and the shadow of her brother approaching (958‒66), which certainly contributes to heightening the disquieting atmosphere of the play: his Medea ultimately appears as a much ‘darker’ and bleaker version of the Euripidean counterpart, also emerging as a full-blown villain, by whom readers are both repelled and fascinated. In addition to this, the vocabulary of extreme passions recurring throughout the play and the heights of anger that the Senecan Medea reaches represent some of the most noticeable variations on the Greek model, not to mention a famous portrait of the heroine by the Nurse (382‒96), which strikingly resembles that of the angry man depicted by Seneca in De ira 1.1.3‒5. In these pages, however, instead of focusing on the notorious ira and furor of Seneca's Medea, I intend to concentrate on another and yet quite strongly related emotion: joy. In general, it may be noted that the bodily felt responses brought about by both anger and joy have in common the category of expansion, unlike fear and sadness (or grief), in which there is a tendency towards contraction. To my knowledge, the emotion of joy in Seneca's play has not received much attention thus far, owing perhaps to the fact that, as mentioned, anger literally steals the limelight. Therefore, I will here attempt to delve into this emotion, which appears to characterize Medea's criminal deeds, especially towards the end of the play, with a view to bringing to the fore its nuances and function. Although joy, at first glance, may seem to be extraneous to a tragic plot staging a filicide, since it is usually associated with good or positive events, it will be argued that this emotion (also verging on pleasure) is particularly fitting for the Senecan character, in that it takes a ‘perverted’ and monstrous form in the play, even coming to distort some concepts central to the Stoic doctrine.