Apollonius of Rhodes gives us the first part of Medeas story in Jason and the Golden Fleece. In that book he dabbles around with Medea, her alchemy, her passion and her divided sense of how to deal with complications thrown her way. This play carries on Medeas story and it isn’t a bundle of ‘happy ever after’ joy. To put it mildly!
There are summaries everywhere so I won’t do that here but I do think Medea gets some of the most powerful lines ever written. I think she compares to Shakespeares Lady Macbeth.
Jason didn’t shine in the Golden Fleece quest as a true hero and his character here is further trashed beyond all hope.

I watched this YouTube review after reading the play and it sort of says it ALL

https://youtu.be/5-qGpKO7gUw