ACE Chemicals Mixing Chamber

From Gordon's location, return to ACE Chemicals. After a brief conversation, shoot the large glowing target on the wall ahead with the Batmobile.

Proceed to the platform where the hanging ramp was previously used. Adjust the hanging ramp to face the hole you just created in the wall.

Drive slowly over the adjusted ramp (avoiding the Afterburner if necessary) to enter the service tunnel.

Follow the service tunnel down successive ramps, destroying the two Diamondback Drone Tanks encountered along the way.

At the dead end, grapple up to the platform just before and above the gate.

In the room below, you'll see two guards and a sentry gun. Grapple to the far end of the room and use your Batclaw to enter a wall vent on either side, accessing the space beneath the floor.

Wait beneath the guards until the turret looks away, then use a fear multi-takedown to eliminate them.

Quickly re-enter the floor space and move to the turret. Exit and disable the sentry when it's not looking.

Interact with the panel on the wall to open the doors, allowing the Batmobile to pass through.

Re-enter the Batmobile and continue through the service tunnels until you reach the next closed gate.

Grapple up to the top of the gate. Drop down and unlock the door to bring the Batmobile through.

Engage the twenty enemies ahead. For an easier approach, drop down inside the gate, activate the nearby wall panel to open it, and use the Batmobile to shoot the enemies, causing them to retreat. You can pursue them on foot if desired.

At the next gate, use the Batmobile eject to launch yourself onto the top of it.

Enter predator mode in the Mixing Chamber, taking down eight armed Soldiers and three Sentry Turrets. Utilize stealth, weak ceilings, girders, ventilation shafts, and floor panels. Clear the back of the room first by entering ventilation shafts to take out a stationary guard and turret, then deal with the patroller.

After clearing the room, approach the door to the mixing chamber in the center and enter.

Interact with the control panel in the center of the room. Four cylinders of Neutralising Agent will emerge from the ground.

Carefully move each cylinder out of its socket and place it in one of the opposite sockets on the walls. Move slowly, watching the colored lights on top of the cylinders. Stop if the lights turn yellow to let them reset before continuing.

Once all four cylinders are moved, a scene will play.

You will then be in control of Commissioner Gordon on the rooftop of the Panessa Studios building. Move down the stairs, enter the door ahead, and take the elevator down.

Enter the lab on the main floor to find a series of cells. Move up and interact.