Superman learns that Mongul has a planet-destroying weapon. Mongul tells Superman that he must lose on purpose, and die, or a planet will be destroyed.

Read More Justice League (Season 1, Ep 13): War World Part 2

Superman and Martian Manhunter are captured by space pirates and sold to a planet that pits aliens against each other in combat to the death.

Read More Justice League (Season 1, Ep 12): War World Part 1