In the previous chapter you defeated the Titan Infected Thug in the Gladiator Pit. The gates of the Pit have been sealed by the Penguin, and Batman needs to find a way out. Use the Remote Controlled Batarang to switch the red emergency override button which is on the other side of the fence. This will open the gate.
Head into the corridor and use your cryptographic sequencer to open the next door. You will now enter the elevator room. Enter the elevator and use your REC electric gun to make it go upstairs. Blow up the ceiling with explosive Gel. Hop off the elevator and keep going along the hallway. You will reach another weakened wall, use explosive get to break through it. Keep going, and you will reach the Torture Chamber. Blow up the wall of ice that is in your way. There will be a cutscene with the Penguin who pins your arm onto the wall with a freezegun. The officers are in distress, they are frozen on the thin ice.
Your goal now is to rescue the officers who are trapped on the ice. The ice is unstable, you need to move slowly, taking your time. Activate the Ice Density Scanner.
Head towards the first cop, G.C.P.D. Officer Forrester . Walk VERY slowly. Breaking the ice and falling into the water could mean death. Free the officer when you finally reach him. Then grapple him to safely.
The officer you rescued will tell you there are two more officers frozen in the room.
Next will be G.C.P.D. officer Whitman. Start approaching his location slowly.
Suddenly a SHARK will jump at you and almost get a bite off you. Penguin will apologize for not mentioning his little "friend" down there, a shark named "Tiny".
Switch to detective mode. You will recognize a maintenance raft with functional anchor points suspended by weak cables susceptible to a Batarang hit. Throw you batarang at the suspended raft to make it drop down on the water. Shoot your batclaw and pull the raft to you. Fire batclaw into one of the latch rings and use it to pull the raft towards the officer. Rescue Whitman and put him on your raft.
Next, you have to rescue G.C.P.D. officer Strickland. Shoot your batclaw at the ring near the last prisoner. Rescue him. He will tell you there are more of them and you will promise to rescue the remaining GCPD officers if they are still alive.
Exit the torture chamber from the north side. Keep going along the hallway. Open the door to the armory. Your goal now is to secure the area. There are 3 hostages on the bridge. The enemies there will be wearing thermal imaging headsets allowing them to spot you hiding in the darkness. This makes it harder to sneak up on them, so the best strategy here is to use a fast hit and run tactic using corner cover. Use vantage points and Detective Mode to survey the area and plan your attack. Another trick is to use the smoke pellet to disorientate an armed enemy and follow up with a takedown. Also, try and use your remote electrical charge to get an armed enemy to fire his weapon and surprise at least one other nearby enemy. If you find yourself in a bad situation, use the Grapnel Gun to escape to a vantage point. Move quickly between vantage points to lose attackers.
One of the Penguin's crew has taken that cop hostage. The only way to save him is to make sure his captor doesnt see you. Take down the hostage taker without being spotted. If the captor sees you, he will execute the hostage and the mission will fail.
Once you've secured the area talk to G.C.P.D. Officer Tom Miller. There are 2 more GCPD officers unaccounted for. Officer Miller will suggest you try the Iceberg Lounge.
Examine the display with Mister Freeze's suit. There is no sign of Fries, just the suit. He can't survive without it. You have to find him before it is too late.
Head back past the torture chamber, and back to the room with the ice. Move slowly across the fragile ice to make sure it doesn't break. Crouched movement is faster then walking but just as light footed.
Board the raft. Make your way towards the Iceberg lounge to the west. Head down the stairs. Enter the iceberg lounge. Penguin will be on an iceberg in the center of the lounge, with the two remaining GCPD hostages.
Attempting to approach the Penguin directly is futile. The Weapon is too powerful. The only person who knows the gun's weakness is Freeze. The Ice blasts are too strong. But Freeze might know how to defeat his own weapon.
Head back to the room with the ice and go to the south hallway. Use the cryptographic sequencer to hack the security system and open the gate. Defeat the three goons in the hallway. Open the door and enter the War Room. Freeze will be there trapped in one of the tanks.
Find the weakend wall and blow it up using the explosive Gel. There will be a big thug, Abramovici, waiting for you behind it. He is armed with a pretty big scythe. The best strategy is to go in, give him a fast beating combo, then dodge out as he swings the scythe at you. Defeat him and his minions, then go through the destroyed wall and use the cryptographic sequencer on the console to open the cage where Victor Fries in imprisoned.
Ask him for Joker's cure. He will tell you to forget the clown. He wants Cobblepot who has his suit and weapons. Tell Fries that Penguin is protecting himself with his ice gun and ask him how to get past it. He will be reluctant to tell you the secret at first, but Batman can be very convincing. Victor Fries will tell you that there is a security override chip he built into the suit to stop anyone from using his weapons against him. He tells you to go get the security override and figure out a way to stop Penguin.
Your objective now is to confront penguin in the iceberg lounge. First you must collect the security override from Freeze's suit to disable the Freeze gun. Head back to the torture chamber. It looks like the ice is beginning to thaw. Jump onto the raft and make your way back to the Armory and to the upper floor to retrieve the security override from the display case where Fries' suit it. Smash the display case and pull the security override chip out from inside the left arm of the suit. This will give you the Disruptor Freeze Override. It is used to remotely disable custom designed freeze gun weaponry. Must be activated in close proximity to the target.
Go back to the torture chamber. Jump onto the Raft. Make your way towards the Iceberg Lounge. The shark will attack your raft. Follow the on screen instructions to beat it. Approach Penguin and select the Override Freeze Disruptor. You will have to get closer to Penguin for it to work. Activate Freeze Gun Override when you are close enough. Batman will give the Penguin a good punch knocking him several feet away. But Cobblepot will draw some remote detonator and detonate the iceberg on which Batman is standing on. Penguin has a surprise for you underneath the iceberg lounge - Solomon Grundy. Prepare for a BOSS FIGHT.
Solomon Grundy is a lot bigger then Batman. Batman's regular attacks cannot hurt him. Observe the three generators. When they are powered down, stand on the generator and quickfire the explosive gel to deploy it to the ground, then detonate them. This will cut off Grundy's power supply. Then go in and beat him. But Penguin will reactivate the generators. You will fight a second round vs Grundy. You have to disable the generators as before. However they now have a protective seal on them which closes and opens. Dont detonate them while the seal is closed. Detonate only when you see the orange smoke. Once all the generators are down, pound on Solomon Grundy again to finish him off. But he will grab you. Struggle with him to break free of his Grasp. Then disable the Generators again and Finish Grundy.
Penguin will attack you now, shooting you with a rocket gun. Storm him and defeat him!
There will be a cutscene. Mister Freeze joins the party. Ask Freeze for the cure. He will say there isnt one. Creating the antidote to the disease that afflicts the clown was easy. Unfortunately, the cure degrades too quickly. It needs a restorative element, some kind of reforming enzyme. Without it, it breaks down before it can help the host. Batman knows a man who has been exposed to that enzyme for centuries - Ra's Al Ghul. Freeze will tell you to bring Ra to him. All he needs is a sample of his blood. One of Ra's Al Ghul's followers overhears the conversation, she breaks out of the glass cage and runs out, leaving a trail of blood which batman can follow to track down Ras Al Ghul.