This would be a direct sequel to 2017 Justice League but my approach to it would be like this:
Movie starts a few years after the first film. The Justice League are pretty much at "Avengers"-type status and popularity like think when The Avengers first formed and they were on everyone's radar. The same thing for JL with them being on everyone's radar and the whole public not only knows about them but loves them. All criminals and or terrorist groups know about the Justice League too and so does the American government. The team is much bigger now and features a roster consisting of the first six members (recast Batman, Superman, Wonder Woman, Aquaman, Flash and Cyborg) along with the additions of Shazam, Martian Manhunter, Green Lanterns Hal Jordan and John Stewart, Hawkgirl and Green Arrow.
At this point, Lex Luthor has officially assembled his Legion of Doom, which consists of villains for almost every hero: Deathstroke for Batman, Metallo and Bizarro for Superman, Cheetah for Wonder Woman, Gorilla Grodd and Captain Cold for The Flash, Black Manta for Aquaman, Sinestro for the Green Lanterns and Black Adam and Dr. Sivana for Shazam.
Early in the film, Deathstroke attacks the Justice League headquarters (Watchtower) with a team of freelance assassins. They cause tons of damage to the Hall of Justice but are swiftly defeated by the League except for Deathstroke, who escapes. The League are relieved and glad it's over, but Batman seems wary of the situation. Taking them down seemed almost too easy. Without notifying the rest of the League, Bruce alone goes down into the Hall of Justice's lower level, where he secretly hooks up a flash-drive to the mainframe of the computer and downloads some files onto it. He goes back to the Batcave and sees Alfred who has been brutally attacked. Alfred then points to where the Kryptonite spear should be, and it is gone. Bruce at this point is in a rage.
Bruce hooks up the flash drive to the Bat-Computer and finds out that a certain folder of files, labeled "contingency", has been apparently wiped clean. And, while he's in the Batcave, the Legion start to attack each Justice League member. Hawkgirl and Green Arrow are taken out swiftly by Black Adam and Deathstroke, and the other members are defeated in unique ways by the other Legion members. The Green Lanterns' rings are disabled by Sinestro. Dr. Sivana forces Shazam to say the word and revert to his child form. The Flash is subdued by Grodd and frozen by Captain Cold. Wonder Woman is tied up in her own lasso by Cheetah. Aquaman is dehydrated by Black Manta, who then proceeds to torch Martian Manhunter. And finally, Superman is bludgeoned by the Kryptonite spear. However, Luthor doesn't want Superman dead just yet. All of the League members are taken back to Luthor's base which is Steppenwolf's old Hive and placed in special cells that use their weaknesses against them if they try to escape.
Batman finally tracks Luthor's Legion there, and he is prepared even if he is by himself as a lone ranger type using the Legion's weaknesses against them. However, Luthor uses some of Brainiac's technology to control the League into going on a worldwide rampage. Batman defeats them all, but at a cost. The League is defunded by the government, and each one of them blames one another for everything that transpired. Luthor is put back in prison, but he knows that "something bigger" awaits them.
Post-credits scene: Desaad informs Darkseid that the heroes of earth have separated and are now vulnerable. Darkseid says "Plot a course for earth. We need to get...the equation."
Movie starts a few years after the first film. The Justice League are pretty much at "Avengers"-type status and popularity like think when The Avengers first formed and they were on everyone's radar. The same thing for JL with them being on everyone's radar and the whole public not only knows about them but loves them. All criminals and or terrorist groups know about the Justice League too and so does the American government. The team is much bigger now and features a roster consisting of the first six members (recast Batman, Superman, Wonder Woman, Aquaman, Flash and Cyborg) along with the additions of Shazam, Martian Manhunter, Green Lanterns Hal Jordan and John Stewart, Hawkgirl and Green Arrow.
At this point, Lex Luthor has officially assembled his Legion of Doom, which consists of villains for almost every hero: Deathstroke for Batman, Metallo and Bizarro for Superman, Cheetah for Wonder Woman, Gorilla Grodd and Captain Cold for The Flash, Black Manta for Aquaman, Sinestro for the Green Lanterns and Black Adam and Dr. Sivana for Shazam.
Early in the film, Deathstroke attacks the Justice League headquarters (Watchtower) with a team of freelance assassins. They cause tons of damage to the Hall of Justice but are swiftly defeated by the League except for Deathstroke, who escapes. The League are relieved and glad it's over, but Batman seems wary of the situation. Taking them down seemed almost too easy. Without notifying the rest of the League, Bruce alone goes down into the Hall of Justice's lower level, where he secretly hooks up a flash-drive to the mainframe of the computer and downloads some files onto it. He goes back to the Batcave and sees Alfred who has been brutally attacked. Alfred then points to where the Kryptonite spear should be, and it is gone. Bruce at this point is in a rage.
Bruce hooks up the flash drive to the Bat-Computer and finds out that a certain folder of files, labeled "contingency", has been apparently wiped clean. And, while he's in the Batcave, the Legion start to attack each Justice League member. Hawkgirl and Green Arrow are taken out swiftly by Black Adam and Deathstroke, and the other members are defeated in unique ways by the other Legion members. The Green Lanterns' rings are disabled by Sinestro. Dr. Sivana forces Shazam to say the word and revert to his child form. The Flash is subdued by Grodd and frozen by Captain Cold. Wonder Woman is tied up in her own lasso by Cheetah. Aquaman is dehydrated by Black Manta, who then proceeds to torch Martian Manhunter. And finally, Superman is bludgeoned by the Kryptonite spear. However, Luthor doesn't want Superman dead just yet. All of the League members are taken back to Luthor's base which is Steppenwolf's old Hive and placed in special cells that use their weaknesses against them if they try to escape.
Batman finally tracks Luthor's Legion there, and he is prepared even if he is by himself as a lone ranger type using the Legion's weaknesses against them. However, Luthor uses some of Brainiac's technology to control the League into going on a worldwide rampage. Batman defeats them all, but at a cost. The League is defunded by the government, and each one of them blames one another for everything that transpired. Luthor is put back in prison, but he knows that "something bigger" awaits them.
Post-credits scene: Desaad informs Darkseid that the heroes of earth have separated and are now vulnerable. Darkseid says "Plot a course for earth. We need to get...the equation."
