When an unexpected and ruthless adversary strikes too close to home, Kara Zor-El, aka Supergirl, reluctantly joins forces with an unlikely companion on an epic, interstellar journey of vengeance and justice.

A young boy learns that he has extraordinary powers and is not of this earth. As a young man, he journeys to discover where he came from and what he was sent here to do. But the hero in him must emerge if he is to save the world from annihilation and become the symbol of hope for all mankind.