Head towards the current objective marker to reach Lacey Towers and eliminate the police force on the surrounding rooftops or balconies to enter the building safely.
Make a right to open the un-taped door in the back corner and enter Sionis’ Safehouse to approach the two bodies in the next room ahead, then use the Evidence Scanner to analyze both of their hands and target the area beneath the chandelier to start recreating the crime scene.
Reconstruct the crimes for both bodies, the wall beside the steps and the floor in front of them, then turn around to scan the broken desk and follow the red trail out onto the balcony to locate the scrap of fabric.
Scan the indicated spot on the kitchen counter to watch another crime play out, then follow the red trail down towards the floor to find the cell phone and complete this mission.
The GCPD Building
Travel to the Batcave to acquire the Concussion Detonator, then return to the city to head towards the current objective marker and reach the next GCR tower to clear out the thugs on the rooftop.
Approach the top right corner of the rooftop and activate Detective Vision to spot the grapple point on the tower in the distance across from you, then fire remote claw at it to create a tight rope and use it to crash through the window on the left.
Hack the nearby device and crawl through the ventilation duct above to reach the roof, then open the control booth at the top to hack another device inside.
Head towards the next objective marker to reach the GCPD and perch on the gargoyle at the right side of building to look down on the pair of men guarding the door below.
Swing over to the gargoyle beside you and eliminate the guard on the balcony below to your left with a glide kick, then turn around to ascend onto the gargoyle above on the right and watch the group of officers split up.
Hit the leftmost guard below with a glide kick to distract the other officers and return to the first gargoyle you perched upon, then fly down towards the pair of men guarding the door and eliminate them.
Continue using the gargoyles to eliminate the officers on the rooftop each time they split up and move through the door that was previously guarded to enter the building, then blow open the wall at the bottom of the next staircase and drop into the shaft to land on the elevator as it descends.
Wait for the elevator to stop before climbing onto the ledge above and enter the ventilation duct ahead to take down the cop on the other side, then pass through the Manager’s Office to eliminate group of officers in the next room.
Crawl through the vent in the corner of the ceiling above to turn left on the other side and fire the remote claw at the grapple point on the far wall to create a tight rope, then walk across it to drop silently into the empty room at the end and exit into the hall to eliminate the officer at the coffee machine.
Hack the device in the corner to your right and move through the next door to reach Swat Division, then take cover behind the boxes on the left to spy on the cops and hit the fire extinguisher in the background with a batarang to eliminate them with a surprise attack.
Enter the Interrogation Room to takedown the cop through the window and approach Loose Lips to interrogate him, then exit into the hallway to pull yourself on top of the doorway to the right and toss a smoke pellet amongst the group of officers below.
Drop into the room filled with cops to eliminate them quickly and blow open the boarded-up section of the wall to enter the area behind reception desk, then exit through the door on the right to proceed into Locker No. 2 and approach the officer around the corner to take him down silently.
Enter the ventilation duct near the floor to hear Gordon’s conversation with his daughter and pull yourself onto the next ledge above to climb the nearby ladder, then walk out onto the perch that overlooks the GCPD Bullpen and swing to the one on the opposite side of the room.
Eliminate the cop below with an inverted takedown and continue moving between the perches to search for another officer separated from the rest of the crowd, then incapacitate them with an inverted takedown or glide kick when no one else is within their eyeline.
If you are spotted while eliminating an officer, drop a smoke pellet before pulling yourself onto one of the surrounding perches above or knock them out first with a flurry of batarangs.
You can also hide in the crawlspaces within the floor of the bullpen to wait for an officer to walk by so they can be eliminated with a silent takedown and there’s a room in the corner with a skylight that can be broken through to incapacitate the cop beneath it.
Finish clearing the bullpen to pass through the door you unlocked previously and sneak past the cops ahead on the right to enter the room at the end of the hall.
Try hacking the next device, then enter the room on the left to take down the cops in the corner and specifically eliminate the shielded enemy by first stunning him with your cape.
Hack the nearby device to drop into the elevator shaft and proceed forward at the bottom to descend the steps around the corner, then sneak up quietly behind the group of cops in the Holding Cells area and open the door on the left without being seen to reach the Infirmary below.
Make your way to the back of the room to approach the crumbling wall marked “Elevator” on the left and blow it apart to enter the Derelict Elevator Shaft, then walk forward to pull yourself onto the next ledge high above and look up to fire the remote claw at the available anchor point.
Walk across the tight rope you’ve created to pass through the nearby ventilation duct and enter the Evidence Locker, then make your way over to the cage in the back right corner of the room and take the Disruptor on the desk.
Return to the Holding Cells and unlock the door that closes by first shooting the jammer above the security device, then defeat the group of thugs ahead and pull yourself onto the second floor landing to drop back into the Cell Block Access area.
Make your way back to the server room’s entrance to disable the jammer and proceed through the door in the corner to encounter Barbara Gordon, then enter the nearby duct to reach the shooting range on the other side and duck behind the crates to listen to the SWAT team’s conversation.
Once the pair of of officers start approaching your position, toss a smoke pellet amongst the SWAT team to disorient them and move in to eliminate all threats by using combination attacks.
Hit the button in the corner and hack the next device above to exit the shooting range, then open the door on the left to activate a cut scene in which you encounter Gordon on the 10th floor and drop a smoke pellet to escape from the gunfire.
Activate Detective Vision to see through the smoke and eliminate the SWAT team, then open the nearby door to exit onto the rooftop and ascend the steps leading up to the helipad to incapacitate the officers at the top.
Head towards the next objective marker to reach the Hamilton Hill building and eliminate the police officers on the two rooftops in front of it, then drop into the alley below and open the indicated manhole to enter the sewers.
Make your way through the sewer tunnel to encounter Black Mask’s men and target the red-clad martial arts expert below to take him out with a glide kick, then eliminate the rest of the surrounding thugs and blow open the nearby wall to enter the Pump Room around the corner.
Pull yourself onto the walkway on the left to follow it around and use the bat claw to reach the enemy on the ledge above at the end, then take him down to quickly eliminate the other enemy nearby and ascend to the next walkway behind you to use the water valve controls.
Use Detective Vision to locate the water valve hatch across from you and pull it down to release the steam, then shoot the grapple point on the opposite wall ahead with the remote claw to slide down the tightrope it creates and take down the enemy through the next window below.
Hack the device on the nearby balcony to locate the next enemy in the pipeline below and perch on the railing to eliminate him with a glide kick, then proceed through the tunnel ahead to reach the GCPD Telecom Room and make your way into the open area behind it to spot the group of thugs on the left.
Use a glide kick to start eliminating the thugs below and activate the elevator to clear out the enemies on the next floor above, then press the indicated button near the monitors to connect to the criminal database and complete this mission.
Gotham Merchants Bank
Head towards the current objective marker to reach the Gotham Merchants Bank rooftop and destroy the breakaway wall to drop through the hatch on the other side, then use the disruptor to hack open the bank access door and swing to the gargoyle on the opposite wall in the next room.
Drop into the corner below on the right to enter the next vent above and break through the floor on the other side to activate a cut scene, then ascend to the gargoyle overhead to swing to the one on the left and lower yourself to the floor.
Perch on the first railing ahead to the left and wait for the signal jammer enemy to pass beneath you before eliminating him from behind, then return to the gargoyles above to pick off the thugs one-by-one until the room is cleared.
Interrogate the remaining enemy and approach the woman infected with Joker gas to scan her body, then exit the room through the door surrounded by police lights and take cover behind the police car ahead on the right.
Toss a smoke pellet in the middle of the SWAT team ahead to disorient and eliminate them, then head towards the current objective marker to reach the next GCR tower and take out the mobsters on the rooftop.
Destroy the green-lit generator box before turning around to approach the opposite edge of the rooftop and eliminate the group of thugs beside the base of the tower to destroy the other generator, then return to the previous rooftop to hack the device in the control room and complete this mission.
Sionis Steel Mill
Approach the current bat signal to perch somewhere that looks down on the section of the steel mill’s yard closest to the water, then take out the sniper on the highest metal platform and pull yourself onto one of the nearby gargoyles above to continue clearing the area by eliminating the thugs in descending order of elevation.
Enter the steel mill via the door out front to drop into the next crawlspace on the left and proceed forward to ambush the group of thugs ahead, then turn around to pass through the door in the back right corner and ascend the staircase to crawl into the vent at the top.
Navigate across the ceiling beams above Sionis’ Office to drop in on the thugs below and clear them out by picking off the gunmen first, then analyze the computers beside the Christmas tree and return to the loading bay to hack the device in the left corner.
Open the next door above to enter the warehouse and toss a smoke pellet into the group of thugs below before sprinting down to eliminate them, then take down the lesser enemies in the second wave of hostiles first and roll away from each of the Enforcer’s charging attacks so that he crashes into the wall.
Yank the enforcer towards you with the bat claw to hit him with an ultra stun maneuver and follow it up with a series of combo strikes until he is defeated, then press the nearby button to send the crane into the breakaway wall above and get behind the metal beams to pull them backwards so that they create a larger hole.
Proceed through the hole in the wall to enter the elevator that rises ahead and examine the body on the floor before hitting the call button to descend to the next floor below, then open the doors in front of you to eliminate the mobsters on the other side and make your way forward into the Drug Lab.
Swing across the gargoyles above to reach the opposite side of the room and execute as many inverted takedowns as possible without being seen, then drop to the lower level of the lab to eliminate enemies from behind and use the floor grates or gliding kicks to finish clearing the area.
Move through the yellow doors at the back of the lab to activate a cut scene in which you encounter Copperhead, then use Detective Vision to scan the area where Black Mask was being held and locate the sweat sample.
Reconstruct the crime scene to follow the red line up towards the ceiling and scan the poison sample you find, then exit the room to move through the next door on the right-side wall and proceed past the various hallucinations ahead to ascend in the elevator.
Strike and counter the Copperhead hallucinations to defeat them one-by-one, then continue moving forward to encounter the real villain and deflect her initial attack.
Fend off the surrounding Copperhead clones as you would any other gang of thugs and watch for her health bar to start draining so you know when you’re fighting the actual boss.
Use evasive maneuvers to move between the fakes and continue striking the real Copperhead or drop explosives to increase the odds of hitting her upon each detonation, then fend off the enemies until the antidote arrives to remove the hallucinations and quickly defeat the boss with a single strike to complete this mission.
The Royal Hotel
After blowing up the canister on your way out of the steel mill, head towards the current objective marker to reach Pioneer Bridge and stand on the indicated spot to pick up Electrocutioner’s signal.
Follow the signal to the Royal Hotel and take out the SWAT team guarding the parking garage entrance, then proceed through the next door below to descend the ramp on the left and follow the road forward to eliminate the pair of enemies ahead from behind as they walk by.
Drop through the window to eliminate the group of thugs below and hack the nearby security console to open the gate so you can strike the button on the other side with a batarang, then fire the remote claw through the hole in the ceiling and ascend to the floor above to open the Parking Gate.
Restart the Main Generator to access the elevator and ride it to the floor above to reach the Hotel Lobby, then take cover behind the barrels on the left to eliminate the thug approaching from around the corner and proceed forward to incapacitate the next enemy on the right.
Hide at the top of the staircase to eliminate the next thug approaching from below and pull yourself onto one of the gargoyles above to help you finish clearing the room with glide kicks or inverted takedowns, then hack the device near the Employees Only door to enter the Security Room.
Following the next cut scene, pull yourself onto the elevator platform to charge its generator with the Shock Gloves and ascend to proceed onto the next steel girder above.
Approach the hole in the ceiling on the left to pull yourself up onto the building ledge above and enter the East Tower’s 10th Floor, then pass through the doors around the corner to encounter the next group of thugs and charge the generator on the right-side wall to raise the security gate.
Slide beneath the gate to eliminate the surrounding thugs and pass through the door in the corner ahead to crawl into the vent above on the right, then jump the gap between the next pair of elevators below to charge another generator and ascend on top of the car.
Pull yourself through the open elevator doors above to execute a ledge takedown and clear out the thugs in the next room ahead with the help of the Shock Gloves, then speak with the Hotel Employee and charge the nearby generator to slide beneath the gate that rises.
Navigate the hallway to approach the open set of windows at the end and activate a short cut scene, then fire the bat claw at the indicated window across from you to slide down it and knock out the enemy in the opposite tower.
Approach the next generator to stop at the corner across from it and use your disruptor to disable the Sentry Turret on the left, then charge the generator to eliminate the group of thugs that approach and proceed through the door ahead to reach the ventilation shaft.
Jump to the next platform around the corner to pull yourself onto the yellow-striped railing above on the right and move left across it to reach the overhead ledge at the end.
Fire the bat claw at the yellow-striped railing on the left to walk across the tight rope and flip the next control switch to pull yourself towards the next grapple point above, then crawl through the duct to yank open the valve cover on the other side and perform a ledge takedown on the enemy around the corner.
Make your way to the West Tower’s 25th Floor and slide beneath the next gate to eliminate the enemies on the other side, then proceed through the door marked “Sleigh Rides” to drop down the elevator shaft and clear out the thugs below on the left.
Enter the next room to create a tight rope between the two grapple points above and pull yourself onto it to glide over to the breakaway wall ahead, then blow it open to hack the console on the other side and drop into the water below to climb the ladder around the corner.
Throw a remote control batarang through the electrified clown eye to have it make a u-turn and enter the other eye socket to hit the fusebox on the other side, then pull yourself through the trapdoor above to follow the tracks and enter the next purple-lit room on the right to start the carnival game.
Watch the pink icons temporarily flash onto each of the four clown heads in front of you and use a batarang to hit the balloons in the same order the symbols appeared, then continue playing the game in this manner until you can pass beneath the gate that opens and eliminate the next group of thugs below on the right.
Pull yourself into the balcony above to activate the Jack in the Box and shoot its head with the bat claw to walk left across the tight rope, then enter the next hallway area to eliminate the hostage-taker from behind and proceed into the Overview Bar.
Enter the floor grate on the left to proceed forward through the duct and stop beneath the second access panel to perform a takedown on the thug above, then finish clearing the room to proceed into the corridor ahead and blow open the wall beside you to pull yourself onto the next gargoyle above.
Pull yourself up into the open window attached to the Ho-Ho-Ho carpet and charge the generator on the right to locate the bombs in the next room, then hack the device in front of the countdown clock and approach the window beside you to jump through the glass.
Fire the bat claw to grab the helicopter above as you fall through the air and defeat the group of thugs on the next rooftop below to proceed onto the East Tower’s 40th Floor, then enter the Swimming Pool area to pull yourself up onto the nearest gargoyle and target a lone thug on the lower level to eliminate him with a glide kick.
Stay low to enter the floor grates and move between the various crawlspaces on the lower level to eliminate as many enemies as you can, then return to the gargoyles above to repeat the same strategy with inverted takedowns or glide kicks.
Finish clearing the room to hack the device on the lower level and activate the next cut scene, then dodge Bane’s first attack to follow it up with a short series of combo strikes and drop an explosive device to stun him by detonating it near his feet.
Hit the boss with a flurry of batarangs each time he flashes red to interrupt his next attack and continue lashing out with combo strikes until Bane juices himself up with Venom.
Flip over the enemy’s head to execute an Ultra Stun assault and perform a Beatdown/Takedown with the Shock Gloves activated to remove Bane’s venom powers, then continue fending him off with combo strikes and counter-attacks until he throws you out the window.
Use evasive rolling maneuvers to dodge Bane’s charging and jumping attacks, then hit him with Ultra Stun to remove his venom powers again and continue draining the enemy’s health by first eliminating the smaller thugs that appear.
Repeat the previous steps to continue inflicting damage on Bane until the next cut scene is activate, then dive off the edge of the roof to fight with the Joker in mid-air and complete this mission.
Hunting Bane
Following the next cut scene in which you take control of the Joker, eliminate the surrounding group of enemies in the Comedy Club to appear as the Red Hood in the Chemical Plant and proceed forward across the walkway to continue watching the memory play out.
Descend the next ramp to continue moving forward each time a flame burst recedes and climb the ladder at the end to crawl into the clown’s mouth above, then activate another cut scene to take control of Batman again.
Proceed through the next series of hallucinations and pick up the glue grenade from the workbench, then fast travel back to the sewer entrance beneath GCPD and defeat the surrounding SWAT team with the help of your shock gloves to access the manhole.
Look for two steam bursts blocking the sewer tunnel to close them off with glue grenades and drop into the next area below to reach Burnley Sewers-East, then pass beneath the Morgue sign to hack the device on the other side and climb the ladder to scan the corpse in the room above.
Approach the nearby computer to analyze the drug and exit the sewers to head towards the next objective marker, then proceed into the tunnel entrance at the edge of the harbor and enter the blue door on the right.
Crawl through the open ventilation duct below and drop into Parks Row-Sewer Access are on the other side, then descend the first set of steps in front of you to walk forward at the bottom and perch on top of the next railing to look down into the stairwell beneath you.
Take out the first enemy below with a glide kick and eliminate the remaining group of thugs in the area to blow open the nearby breakaway wall, then toss a glue grenade into the water to create a raft and pull yourself between the grapple points ahead to ride it forward through the tunnel.
Open the next set of doors ahead to eliminate another group of thugs and proceed forward into Bane’s Field HQ-Entrance, then enter the room below to activate Detective Vision and inspect the various points around you.
Exit through the hole in the upper left corner of the room to activate a cut scene and exit the sewers to complete this mission.
Gotham Pioneers Bridge
Head towards the current objective marker to reach Gotham Pioneers Bridge and activate the next cut scene, then descend towards the cops below and eliminate the one on that balcony that overlooks the rest of the group.
Enter the Maintenance Room to approach Gordon and activate the next cut scene, then hack the console ahead on the right to enter the elevator shaft and pull yourself onto the ledge above.
Pull open the next vent cover to reach the generator above and charge it up with the shock gloves to raise the elevator, then use glue grenades to clog the three valve openings on the other side of the shaft and jump across the gap to continue your ascent.
Use the bat claw to reach the door at the top of the shaft and enter the Boiler Room Maintenance Corridor to crawl through the next ventilation duct above, then swing to the surrounding gargoyles and start eliminating the enemies below with glide kicks or inverted takedowns.
Interrogate the remaining thug to learn the locations of the bombs and approach the wired oil drums on the upper level to disarm the first one, then exit the boiler room to ascend in the elevator car and climb the next ladder above to reach Train Maintenance.
Charge the nearby generator to raise the elevator and blow open the next wooden wall to eliminate the thugs on the other side, then speak with Branden to counter his attack and climb the ladders above to enter the Train Station.
Shoot the grapple point above on the left with the remote claw to pull yourself up onto the tight rope it creates and throw a smoke pellet at the enemies on the upper level of the building across from you, then hit the nearest one with a glide kick to start clearing them out and continue defeating each new one that approaches.
Speak with the hostages in the train car and pass through the door on the lower level to ascend into the Control Room, then activate the lift to disarm the bomb that lowers into the train station and exit through the doorway in the corner to proceed down the glass corridor.
Charge the next generator to enter Maintenance Corridor (South) and approach the wooden wall on the left to fall through the floor, then pull yourself into the train car above to jump out the side door and walk along the twisted beams to spot the grapple point below on the right.
Create a tight rope to walk across and approach the wooden wall to pull yourself onto the next train car above, then take out the sniper below to the left and use the gargoyle in the distance ahead to clear the gap beside you.
Swing to the last gargoyle to drop behind the pair of snipers below and eliminate them quietly to access the South Pillar Electrical Room, then enter the floor grate at your feet to ambush the group of thugs ahead and clear them out.
Hit the button on the truck to disable the electrified gate and disarm the bomb on the other side, then exit the room to speak with Alfred and return to the area with hanging train cars to glide down to the section of tracks below on the left.
Blow open the wooden wall on the opposite side of the room to crawl beneath the pipes ahead and charge the generator in the corner to enter the Train Station, then drop into the floor grates on the left to lie in wait and ambush the next enemy that walks by.
Enter the room around the corner to immediately turn right and pull yourself onto the platform above to execute a ledge takedown on the sniper, then drop into the floor grates at the center of the station to eliminate another enemy on the opposite side of the area.
Pull yourself onto the upper level to eliminate another pair of thugs and proceed beneath the large fire door in the corner below after Alfred opens it, then charge the nearby generator to reach Pioneers Bridge (North) and ascend onto the next twisted twisted metal girder above.
Head left to eventually pull yourself up on top of the bridge and eliminate the next group of thugs below to activate a cut scene in which you encounter Firefly, then hit him with the bat claw, a glue grenade and flurry of batarangs to start inflicting damage.
Roll sideways to dodge the boss’ initial flame burst attack and him with another glue grenade followed by a flurry of batarangs, then fire the bat claw to take hold of Firefly and pull him towards you to strike a critical blow.
Repeat the previous step to continue draining Firefly’s health until the next cut scene is activated, then pull yourself onto the indicated beam outside and proceed forward across it quickly to return to the bridge above.
Roll towards the right across the bridge to dodge Firefly’s next attack and jump to the blue car above to slide beneath the truck on the left, then continue sprinting forward avoid the incoming bombs.
Continue rolling away from the flamethrower attacks and draining the boss’ health with your gadgets until he ftries to escape, then follow the on-screen prompts to defeat Firefly and complete this mission.
Blackgate Prison Redux
Approach the bat computer to restore Detective Vision and activate it before perching on the railing to the left, then look towards Alfred’s body on the rocks directly below and glide down to him to remove the rubble.
Shock Alfred’s body repeatedly to bring him back to life and watch the next cut scene unfold, then pull yourself on top of the gate ahead on the right and toss a smoke pellet into the group of thugs below before gliding down to eliminate them.
Drop through the manhole in the corner to enter the sewers beneath Blackgate Prison and blow through the next section of wooden floor ahead to fall into the area below, then pull yourself onto the ledge above and use the remote claw to cross the gap in front of you.
Use the remote claw again to cross the next two gaps above the electrified water and enter the corridor above at the end to blow through the wooden wall on the left, then glide down to the ledge below to destroy the fusebox around the corner.
Return to the gap you glided across and create a raft in the water below to pull yourself through the next tunnel ahead, then enter Sewage Flow Control Room A above on the left to approach the button in the corner and look out through the window to see the electrical activity on the other side of the tunnel.
Throw a batarang out the window so that it passes through the electricity in the distance and turn it left to hit the fuse box in the corner on the other side, then exit the room to create a raft in the next pool of water below and pull yourself over to the wooden wall ahead to blow it open.
Proceed forward with the help of the glue grenades by creating rafts and clogging steam pipes until you reach the Prison Maintenance area, then eliminate the group of criminals to charge the nearby generator and climb on top of the elevator that falls to rappel up the shaft.
Crawl through the next ventilation duct to exit out the first grate on the right and take cover beside the doorway on the left to scope out the scene ahead using Detective Vision, then ambush the nearby guard from behind and pull yourself onto one of the gargoyles above to start clearing the room with glide kicks or inverted takedowns.
Eliminate the snipers on the upper walkways and ledges first, then use smoke pellets if necessary to mask your escape or to take out multiple enemies at once if they’re close enough.
Once you’ve cleared the room, approach the hostages located within the room at its center and speak with Harleen Quinzel to proceed into the Cell Block B Access area below on the right.
Eliminate the group of thugs in Cell Block B to climb the next staircase in the corner and make your way across the second floor to encounter Deathstroke, then descend the steps on the opposite side of the room to defeat another gang of criminals in the area below.
Proceed into the Panopticon Access area to eliminate a third wave of enemies and enter the next room ahead to activate a cut scene, then roll sideways repeatedly to dodge Bane’s initial charging attacks and his jumping ground pound attacks.
Hit Bane with an ultra stun attack to follow it up with a beatdown combo and continue assaulting the boss in this way until your shock gloves are charged, then use them to drain the enemy’s health and defeat the group of smaller thugs that appears next.
Continue fighting Bane until a cut scene is activated in which he breaks you over his knee and the GCPD arrive, then take down the next group of thugs by diving away from or over the boss each time he charges.
Wait for Bane to execute a ground pound that knocks out all of the other thugs and move in close to attack him by starting with an ultra stun combo, then continue clearing the area of lesser criminals and take another two chunks out of the boss’ health bar.
Continue attacking the boss until the next cut scene is activated, then shock Bane repeatedly to bring him back to life and start the fight all over again in the Maximum Security Ward.
Wait for Bane to walk away, then sneak up behind him in the next corridor to execute a silent takedown maneuver as soon as he passes by one of the electric generators within the surrounding walls and follow it up with a series of combo strikes.
Retreat from Bane once he escapes from the electricity to drop into the nearest floor grate and wait for the boss to approach before executing a second takedown maneuver, then continue attacking in this manner until the next cut scene is activated and fire the bat claw at the two indicated grapple points to defeat this enemy for good.
Proceed through the control room ahead to pull yourself onto the ledge above in the right corner, then crawl into the next ventilation duct to drop into Death Row on the other side and activate a cut scene.
Defeat the next group of thugs with the help of Gordon to enter the Prison Chapel and activate another cut scene, then follow the on-screen prompts to defeat the Joker and complete the game.