In the script, Batman creates a spy-satellite, Brother Eye, to monitor Earth's superheroes and keeps detailed files on how to neutralize them should they go rogue, which are stolen by Maxwell Lord, a powerful telepath who wants to use a nanotechnological virus to turn the entire planet into a hive-mind under his control. After a failed attempt to use Batman's counter-measures to assassinate Earth's heroes, they join forces to stop him as the Justice League, facing off against the OMACs, an army of androids capable of adapting to their abilities.
Miller wanted to cast young unknowns for the lead roles, and after a lenghty audition process, settled for D.J. Cotrona as Superman, Armie Hammer as Batman, Megan Gale as Wonder Woman, Common as Green Lantern John Stewart, Adam Brody as the Flash, Anton Yelchin as Kid Flash, Santiago Cabrera as Aquaman, Hugh Keays-Byrne as Martian Manhunter, Jay Baruchel as Maxwell Lord, Teresa Palmer as Talia Al Ghul, Zoe Kazan as Iris West, and Stephen Tobolowsky as Alfred Pennyworth.
However, production faced setbacks from the beginning. The 2009 writer's strike hit it hard, preventing the Mulroneys to revise the script based on WB's notes, leaving it to Miller to do it in order to meet the production schedule. The casting choices faced insane, FANT4STIC-level fan backlash that made the studio jumpy with the prospect of the biggest target audience boycotting it. Miller insisted that they film it in Australia, but the government issued taxes that WB refused to pay up, leading to a months-long dispute in which no one was budging. And all while this was going on, WB was spending mad money with pre-production, going as far as building sets without even having a place to film.