You can only find this free battlestar after unlocking the A Looming Threat Loading Screen.
This is the A Looming Threat Loading Screen for reference:
The superheroes are looking at some location on a digital projection of the map.
If you zoom in on the digital map the superheroes are looking at, you will see a projection of a battlestar. The spot is found near some trees on a hill just southwest of Fatal Fields
See screenshots and maps below to help find the location of the secret battlestar.
- You can only locate the secret star after you have unlocked the A Looming Threat.
- There is a bug where sometimes the battle star does not show up. If that happens try logging out of the game, then equipping the A Looming Threat in the Locker as the active loading screen, and then trying again to go to the location.