MISSION 08 - Miagani Island Base
Objective: Infiltrate the tunnel network under Miagani Island
Once in the tunnel you will reach a dead end with enemies just beyond. Back up in the tunnel a little bit to spot an exhaust fan in the roof with a grab point. Use the power winch on the fan while in to rip it out of the way, giving you foot access to the rooms above.
Climb up and start looking around, you'll be able to punch through the dividing wall after your talk with Robin. Continue your demolition man routine until you reach a room with a wall vent for you to remove. Travel through the vent until you reach a room with a large exhaust fan swirling away below. Hmm, looks like you don't want to mess up unless you want to be Bat-suey.
Some use of gadgets here will be needed. The Line launcher and remote Batarang primarily. Select the Line Launcher and target the wall on the far side of the room to cross over the fan safely. From this position, you'll need to use the Remote Batarang to press a nearby button (you'll see it in detective vision mode). You'll need to move around to the right side of the wall in front of the switch with the Batarang to find a large hole. Guide the Batarang through and slam it into the switch to open a nearby wire gate.
Now the gate is open, you can use your Line Launcher again to cross through it and above the blades. After passing through a room with several plants inside, you'll be facing another huge exhaust fan. Once again use your Line Launcher to get to the far side of the room.
Select the Remote Batarang and guide it up through the hole in the wall to the right of the metal bars where the switch is to get it in the small room. After it connects with the switch, you'll be able to use your Line Launcher to pass through the now open gate. After striding down another hallway, you'll arrive on a balcony/ ledge overlooking large numbers of Arkham Knight's forces below.
Note: There is a Riddler trophy sitting out in the open on this balcony for you to grab
Despite the temptation, don't take on all of Arkham Knight's forces at once. Instead grapple around the room (towards the door with the two active drones next to it) until you find a vent panel on the wall to the right. Use it to crawl underneath the forces, moving past them until you can jump out in another room. When you do, a quick scene will take over (note: you can counter during the scene if you are fast enough, to prevent taking damage).
Huh, looks like Batman's cocked things up. Oh well, nothing beating down legions of henchmen won't fix. There will be a lot of guys (30+) to fight here, and the introduction of some new big ones too (they can only be defeated by using the beatdown attack - B X/ Circle Square). Remember to focus your displeasure on medics first when they show up, the big brawlers second, then ninjas and finally regular militia after that. Or just punch everything if that floats your boat instead.
Once they are all taken out, a tank will start spraying machine gun fire across the room. Immediately get out of it's field of attack. Once that's done, use the power panel in the room to open the metal shutters and take remote control the Batmobile. Destroy the wall blocking it's path and take out the drones waiting on the other side. Laugh as you shoot the stuck drone in the tailpipe.
Exit the henchman strewn room via the now clear doorway (isn't it great how the drones disintegrate when they explode? Makes leaving much easier). After interacting with another power panel you will be on the streets again.
You'll be thrown into another high speed chase as you race after the Arkham Knight's convoy. Stay close and take out his support vehicles with your immobilizers (B/ Circle) whenever they lock on. Once he is alone, start to whittle down his health bar (shown in the top right). When the bar empties, a scene will take over and you'll have some interrogating to do.
Objective: Rendezvous with the Batwing to equip a new secondary weapon for the Batmobile
You will get an introduction to whichever secondary weapon upgrade you selected back in Wayne Tower. Hold Y instead of X to deploy the Virus when you have enough secondary charge if that's what you selected. You will need to take on a group of sixteen drones to prove you have a handle on your new toy (although you don't actually have to use your new weapon at all to progress). After leaving the drones and missile drones strewn across the sidewalk, it's on to the next mission.