The largest set piece shown off by Warner Brothers for the Justice League movie was the Gotham City ventilation shaft. The tower has already appeared in the DC Films universe during Batman v Superman: Dawn of Justice's climactic fight sequence against Doomsday, however this time around, the action will be taken inside. More specifically, the location is Stryker's Island, the famous DC Comics prison.
Production designer Patrick Tatopoulos guided Comicbook.com and a group of other press on a tour of the facility which matched any dark, gritty picture of Gotham City one could ever imagine. The worn brick outside and gravely, rusted interior set the tone for what will become an epic action sequence with several heroes - but we'll get to that.
Once inside, catwalks and old spiral staircases find themselves above a cement floor. Bricks made of foam lay in the corners around a slightly raised surface which is soft for impact (as pointed out by Tatopoulos). Broken glass windows make up two sides, one solid brick wall the third, and another brick wall with a large, gaping hole claims the fourth. Someone busted into (or out of) this place. According to Tatopoulos, the room is topped with a huge vent fan.
The upstairs leads to a busted bridge with green handrails (to be edited out). The bridge, when connected, leads to the outside of the facility where old, incomplete train tracks are set on the ground with big pieces of rubble. Signs on the building indicate it was created in 1929. The outer parts of the set also contained a crane rig which had lights placed on it to match that of the front side of Batman's Crawler. No full Crawler was ever built, as CGI will supplement the practical cockpit.
So, what goes down on in this ventilation shaft? Based on the information gathered around the set of Justice League, it's pretty clear…
"It's a tunnel they were gonna build between Metropolis and Gotham, and it had been abandoned, so the project never really went forward," executive producer Deborah Snyder explains. "But there's the remains of what started to be this tunnel, and there's a great action set piece that takes place in it. It's pretty hard to get the Batmobile through there. So it's nice to have the Crawler, which kind of can maneuver."
Batman, Cyborg, The Flash, and Wonder Woman will be directed to the island by Commissioner Gordon in an earlier scene atop a Gotham City roof. They are hunting for a nest of Parademons, which Deborah Snyder confirmed to be a part of the film. Concept art shown in the Warner Brothers studio showed this same ventilation shaft serving as that very nest, as well as the Crawler making its way through tunnels and roasting Parademons with flamethrowers and other weapons.
Other concept art also showed the Crawler coming to a flood and being abandoned by the apparent first four Justice Leaguers. Given Tatopoulos tells us the Crawler is not in Justice League very much, we can only presume the attack on the Parademon nest ends with a flood for the unique Bat-vehicle.
Justice League is set for release November 17, 2017.