Orestes and the Furies. To find out more about Orestes, see this Wikipedia article: link; for information about the image: image source.
After Clytemnestra and her lover Aegisthus murdered Clytemnestra's husband, Agamemnon, their son, Orestes, murdered Clytemnestra and Aegisthus in revenge. According to the version of the story told by Aeschylus, Orestes then went mad and was tormented by the Erinyes (Furies) for his crime. You can read more about Aeschylus and his "Oresteia" cycle of plays in this Wikipedia article. The painting of Orestes and the Furies below is by John Singer Sargent.
You can also find more myths and legends for the week of August 12-18 here. For more information and links to the actual javascript code, see the Myths & Legends Widget Reference Page.