Medea is a character from a play written a long time ago by a man named Euripides. Medea was once married to a man named Jason, who went on a journey and met another woman he wanted to marry instead. This made Medea very, very angry, and she wanted to get revenge on him.
But Medea's revenge wasn't just a simple prank or mean name-calling. Oh no, Medea wanted to hurt Jason the way he hurt her. So she came up with a very, VERY bad idea. She decided to kill their two children together, and make Jason suffer the same way she suffered when he left her for another woman.
Now, this is a terrible idea, and most people would never do something like this. But Medea was so angry and upset that she thought it was the only way to make Jason feel the same pain she felt. In the end, she did end up killing her children, which is very sad and horrible. But it just goes to show that sometimes people can do very bad things when they are hurting inside.