Kara Zor-El, Superman's hot-tempered cousin, has finally found peace and purpose away from Earth and its heroes. Now known as Superwoman, she watches over the Moon and the refugees from across the galaxy who have congregated there. But all of that is about to change when a spaceship piloted by a runaway alien crash-lands and turns Kara's world upside down! Does this fugitive come in peace? Or does this arrival bring war to our hero's front door?