While Disney and Marvel were busy shooting “The Avengers” last year, Warner Brothers quietly began getting its own all-star superhero pic back on track, tapping “Gangster Squad” scribe Will Beall to write “Justice League,” based on the WB-controlled stable of DC Comics superheroes.Warner Bros. had no comment on the top-secret hire, which, due to its timing, was more in anticipation of — rather than a reaction to — the box office success of “The Avengers.” Beall has yet to turn in his “Justice League” script, though he has become a favorite scribe of Warners. He’s been linked to the studio’s proposed “Lethal Weapon” reboot and several other projects at WB, which will release “Gangster Squad” on Sept. 7. Warners originally tried to mount a “Justice League” movie several years ago, with George Miller directing from a script by Kieran and Michele Mulroney. That iteration was set to star Adam Brody as the Flash, Megan Gale as Wonder Woman and then-newcomer Armie Hammer as Batman. Back in January 2008, the studio cited a lack of tax breaks as the main reason it pulled the plug on the project, which also needed a rewrite that wasn’t possible because of the writers’ strike. DC Comics is a vital component of Warner Bros.’ intellectual property, as “Green Lantern” scribes Marc Guggenheim and Michael Green were tapped to write “The Flash” for director Greg Berlanti, while another “Green Lantern” scribe, Michael Goldenberg, was hired to write “Wonder Woman.” Additionally, Brad Peyton is working on a new draft of “Lobo,” while John Kamps and David Koepp are developing “Spy vs. Spy” as a potential directing vehicle for Ron Howard. WB also developed the “Aquaman” property several years ago. Beall is repped by CAA and Management 360.