The film is directed by Matt Peters from a story by Ernie Altbacker and stars Justin Hartley and Anson Mount as Superman and Batman, respectively.

The film, set in a separate continuity from the main DC Universe, follows Superman’s descent into madness after being tricked by Joker into killing his pregnant wife Lois Lane and detonating a nuclear weapon that destroys Metropolis.

The film adapts elements from both the Injustice video game and its prequel comic book series (primarily the Year One arc), but tells an original narrative which diverges from the source materials.

The Flash finds the Scarecrow dead in his lab and his supply of fear toxin missing before being killed by a trap laid by Joker.

Lois's husband, a panicking Superman, eventually finds Joker and Harley hiding on a submarine but is attacked by Doomsday, whom he punches into space.

As the other heroes arrive and apprehend the Joker and Harley, Batman realizes that they have mixed the fear toxin with Kryptonite and used it to make Superman hallucinate that he is fighting Doomsday; in reality, he has beaten Lois to death.

While Green Arrow takes Harley to his hideout to protect her from Superman, the latter reveals his identity before the United Nations and announces his intentions to bring peace to Earth, by force if necessary.

The Justice League is left divided over Superman's actions; some members, such as Wonder Woman, support his new methods, while others, like Batman, keep their no-killing vow.

Meanwhile, the United States government becomes concerned that Superman will interfere in their operations, and have Mirror Master kidnap Jonathan Kent as leverage against him.

Harley, who escaped Green Arrow's capture and decided to become a hero, releases the inmates, forcing Batman and Superman to temporarily put their differences aside to fight them.

After Superman transforms the Earth into a police state using surveillance drones, Batman has Plastic Man break Mister Terrific out of prison and leaks video footage of Superman killing a group of partying teenagers inspired by Joker to ruin his public image, shocking Wonder Woman as a result.

[9] The film made its linear debut in the United States on Adult Swim's Toonami block on February 19, 2023.