That's not her son. I think that's Achilles.
It's the tale of Agamemnon. the general who led the Greeks to war against Troy. To get the army to follow him, he mislead and sacrificed his own daughter to the gods.
Needless to say, her mother, Clytemnestra (Kate Mulgrew) was NOT pleased.
Assuming this modern telling is similar to the historical account, I'll let you guess what happens to HIM in the end.