Weeks after the events that led to Lex Luthor’s arrest, the impeachment of his presidency, and Batman’s success in saving the world from the impact of an arriving meteor, a spaceship lands in Gotham City Harbor and a young girl with no knowledge of English or any other human languages emerges. Upon arrival, she accidentally causes all sorts of havoc with her Kryptonian-like powers until the Dark Knight catches her with a piece of Kryptonite from the ship. With Superman’s help, they discover that the girl is Kara Zor-El, the niece of Jor-El and Superman/Kal-El’s biological cousin. While Superman welcomes Kara with open arms and teaches her English and how to behave in society, Batman remains suspicious.
If you're of the belief that Superman is a candy-ass as I was up until a few years ago, this movie is worth looking into. For the most part, you may as well forget that Batman's in it as for the most part it feels like the Superman/Supergirl show. There are some great fights (namely between Superman and Darkseid) and the story has its moments but I can think of several other books DC should have made before this.