From the back-cover:
In the red corner: Rocketed from the planet Krypton and powered by Earth's yellow sun, it's the Man of steel- SUPERMAN!
In the blue corner: Raised in Louisville, Kentucky, and powered by a lifelong study of the sweet science, it's the Greatest himself- MUHAMMAD ALI!
Together, the Man of Tomorrow and the Champ are two of the mightiest warriors the Earth has ever known. Now they must face their greatest challenge yet:
An alien armada has threatened Earth with total destruction unless we select a champion to fight for our very existence. Superman and Ali are forced to duke it out in the boxing ring to determine who will have the honor.
It will take both heroes to stop this alien menace. But how can the two warriors team up... when only one will be left standing?
- ISBN: 978-1-4012-2841-5