Yep, Shmoopers—he's at it again. Everybody's favorite dirty old god is up to his usual tricks in this story.
The one thing the king of the gods likes more than bossing all the other gods around is seducing every pretty young thing he can lay his hands on. Seriously, Zeus is always changing into some weird form—a cloud, a swan, a shower of gold—to seduce a girl. Callisto is only one in a long, line of conquests. Leda, Europa, Alcmene, Danae, Leto… the list goes on.
The fact that the Greek king of the gods is such an unrepentant philanderer is kind of interesting by the standards of many modern day religions. What does it say that the big guy in the sky, the dude in charge of everything, doesn't give two flips about stepping out on his wife, Hera? But we have to remember that in ancient Greece, Zeus's cheating might not have been so scandalous.
In the end, Zeus does help out poor Callisto, though it definitely takes him a while to get around to it. He doesn't do diddly-squat to help when she's transformed her into a bear, but he steps in to stop their son, Arcas, from unknowingly skewering his mom with a spear. Apparently that would be too messed up even for Zeus, who usually has a pretty iron clad conscious when in comes to the typically horrible fates of his romantic conquests.
So does Zeus redeem himself? What do you think?
P.S. For tons more on Zeus, check out Shmoop's files on the big guy.