Infinity Ward revealed a network of tunnels under Verdansk in a trailer released Tuesday for Warzone and Modern Warfare Season 6.
In the trailer, a pair of new operators named Farah and Nikolai appear in dark, underground tunnels. Nikolai tells Farah that Zakhaev, the primary enemy in Modern Warfare, has been using the tunnels to move around Verdansk in secret. While Farah fends off a group of enemy soldiers, Nikolai turns the power on in the tunnels, reviving the trains that thread the tunnels.
These underground trains will likely play a part in Warzone Season 6, allowing players to move around Verdansk faster than ever before. Exact details concerning the trains remain unknown as Infinity Ward builds toward Season 6's release Sept. 29.