You now need to go back towards the server room's entrance, which you now will be able to unlock, thanks to the disruptor. Again, walk through the venting shaft, and reach the area with the Derelict Elevator Shaft. Jump down and walk through the Infirmary, to return to the Holding Cells. Use the disruptor on the device that is blocking the signal, which is located above the control panel (you need to press and hold down the trigger/key for several seconds). Only after you do that, use the , Cryptographic Sequencer and solve the hacking mini-game, which will allow you to determine the correct password. (the screenshot).
You have probably already noticed that some of the prisoners freed themselves in the meantime and, as a result, you will have to fight them. You should, first of all,, watch out for the armored enemy with the green tubes sticking out of his back. To the extent it is possible, avoid this character's charges (red symbols above the head) because, otherwise, Batman may be caught and sustain damage as a result of attacks of the other prisoners (if this happens, you need to free yourself by tapping rhythmically the key/button appearing on the screen).
The best method to deal with the abovementioned enemy is to stun him with the cape, and cause successive tubes to be ripped off his armor. In the meantime, avoid the attacks of the other inmates as well, especially the ones armed with knives. Also, you should search for opportunities to hit the enemies with batarangs if they are trying to lift the propane tanks, thanks to which they will be much easier to deal with. Continue fighting until you defeat all of the prisoners.
[New Challenges: Campaign Challenge]
[New Challenges: Custom Challenges)]
[New Challenges: Combat Training Challenge]
Use the hook to make it over to the balconies above [Cell Block Access] and continue your path along the basement of the precinct. After you get near the elevator shaft, use the hook to your aid and return up to the [Basement Access] [GCPD - Investigations]. stop in front of the server room and use the disruptor to sabotage the device above and then select from the inventory the Cryptographic Sequencer and determine the password (the screenshot). you may now watch the cutscene of the visit to the server room and conversation with Barbara Gordon.