Assault on GCPD HQ

Exit the precinct and return to the car park. A scene will play, and enemies will emerge from APCs. Use the Batmobile to quickly eliminate them. If any enemies enter the precinct, exit the Batmobile and clear them out in the holding cells area.

Return to the car park and enter the Batmobile. In Battle Mode, use the Power Winch on a ventilation fan near the roof to create an opening. As Batman, use the Batclaw to grapple up and follow the linear passage through the tunnel and vents. Enter the elevator shaft and grapple to the top. Exit the vent for a scene.

After the scene, go to the western side of the rooftop to find the generator. This won't work, but a communicator chat will provide an alternative option.

At the northern end of the rooftop, above the car park entrance, use your Remote Hacking Device on the Dragon Drone outside to temporarily blind it. Drop to ground level and crawl through the half-open gate before the Dragon recovers.

Move down the ramp and engage a group of militia forces. This fight includes a shielded Brute and stun stick Soldiers. There are 14 Soldiers total and melee weapons. Overload stun stick enemies to stun them, and try to leave the Brute for last.

After the fight, move to the alcove next to the locked gate. Hit the three generators on the wall with your Remote Electrical Charge gadget to open the door.

Enter the car park and get in the Batmobile. Head for the exit to prepare for a large Drone Tank battle. During this fight, your ally can hack Drone Tanks, causing explosions, turning tanks against each other, or creating EMP blasts. Shoot the targets that appear on screen when a hack is ready.

There are 62 Drone Tanks in total, including Twin Rattlers, Dragons, Mambas, Diamondbacks, and two Missile Launchers. Utilize your ally's hacks and the level 4 Missile Barrage as much as possible. If overwhelmed, drive through the weak wall next to the garage entrance to reveal a waterfront road. Back up out of sight to draw enemies through the destroyed wall, creating a bottleneck for a more controlled fight.

After the Drone Tank battle, you'll receive a message to head for the rooftop.

On the rooftop, you'll face a large group of militia. Initially, there are five Soldiers (two with shields) and a Brute with stun sticks. Use melee weapons and environmental takedowns (hatches, pipes, fences) to your advantage, especially on the Brute.

Around halfway through the fight, a helicopter will drop off a Medic and five Combat Experts. Immediately prioritize eliminating the Medic to prevent him from reviving or electrifying enemies. Once the Medic is down, systematically take down the remaining enemies.