This painting by Peter Paul Reubens (c. 1625) shows Thetis, the divine nymph who was the mother of Achilles, dipping him into the River Styx in order to obtain immortality for her son. As you can see, she holds him by the heel, which is why Achilles ends up with the proverbial "Achilles' heel," the one spot where he is not protected. In the end, Achilles will die young, killed by an arrow which strikes him in that one spot of vulnerability. Meanwhile, in the background you can see Charon ferrying the dead souls across the river in his boat:
The colors in this image are certainly very striking; other images of this painting online (for example here) are much darker. I am curious if anyone has information about just Rubens actually painted at the time and whether the colors we see here are anything like the colors he would have used, or whether this is just an example of digital photography gone a little wild!