Batman: Arkham Asylum Guide - Walkthrough
Old Sewer / Bat Cave
Ahead of you is a group of thugs – one armed, the rest unarmed.
This is a straight forward fight – just target the armed thug first and take him down so you do not have to worry about being shot. Avoid the knife thug while you take the others down, and then stun him and take him down – easey peasey!
You call Oracle after the fight and let her know where you are going, and now it is time to go there! Move ahead and then zip up to the next level and move through the duct, drop down and move along the tunnel and you will reach a door with a scanner – it scans you and you are admitted to The Batcave! How cool is that?
Run straight ahead and jump the gap, make a left up the stairs and you get a CS of you making the antidote. As you are explaining the plan to Oracle, Ivy's plants invade the Batcave, and you do a nice ninja dance to avoid them. Once they are settled in, you re-equip your Batbelt Batgear, including a new tool, the Ultra Batclaw – a device that allows you to pull down weakened walls from a distance – now that will male collecting the rest of the trophies a snap!
Now you need to head for Poison Ivy – but first you have to find a way out because the plants have blocked the ways we know about. This is not a serious problem though, because we just got a new toy and they never give you a new toy if you don't have a chance to use it right away, do they?
On the south wall of the Batcave there is a weakened wall that you can pull down – so do that, then Line Launch across and look up – see the zip point? Well? Get up there! Head into the cave here and walk to the edge outside for a nice CS that reveals the route you need to take. Get a good running jump 'and glide to the landing spot – just glide between the two needle-like rocks and you will land okay – now notice the Trophy here and pick it up!
Zip up to the second step then climb the third and use your Line Launcher to bridge the gap, then head into the cave here. There is a zip-point above and once you are up there, you can see there is some gliding in your future. Now, you see the needle-like rock tower on the right? Mid-way down that is a ledge with a Riddler Trophy, so go ahead and glide down and grab that for 200 XP and another challenge unlocked.
Now look SSE and you can Line Launch to the rock spire below where we just were and then zip up to the ledge. Go back inside the cave and zip up two points and you will arrive at a ledge – look out to the NNW and you will see the opening we want to Line Launch to. Do that then enter the cave and run through it to a perch over an area we are already familiar with.
Do a running glide off of this ledge and land on the walkway below – now zip up to the shaft on the wall here and move through the duct to the Old Sewer, turn left and make your way back to the stairs – kill the pod here then move to the next one, dodge its spore balls and kill it. One more pod further down the hall so kill that, and then enter the Main Sewer Junction.