Heracles and Alcestis. To find out more about Alcestis, see this Wikipedia article: link; for information about the image: image source.
The story of Alcestis was made famous by Euripides' play. Alcestis was married to Admetus who had won an unusual gift from the god Apollo: when it came time for Admetus to die, he did not have to die - but he had to find a substitute to send to Hades in his place. So, when the time came, Admetus' loving wife Alcestis was the only one willing to take his place. The god of death took Alcestis away and Admetus' old friend Heracles then showed up at the house. Distressed at what has happened, Heracles managed to steal Alcestis away from the god of death and brought her back to Admetus, the happy ending which you can see in the image for today.
You can also find more myths and legends for the week of March 11-17 here. For more information and links to the actual javascript code, see the Myths & Legends Widget Reference Page.