Lego Batman 2: DC Super Heroes Walkthrough Part 7 – Arkham Asylum Antics, Part 1
To the Batcave
Go to the vehicle builder that is in the center of the lot. Call out whichever vehicle you would like. Once you have summoned the vehicle, hop into it. Alfred will ask you to test the weapon system inside it. There are 5 Silver statues that can be destroyed around the lot. They are big and a little gaudy, so go ahead.
Once the 5 statues are destroyed, the gate will lower underneath the roller coaster track. With that, it is time to head for the Batcave itself. Follow the phantom blue chips along the winding road. They make a sharp left turn along the way. If you overshoot, just turn around and they will readjust to show you the way to the console that will let you into the Batcave.
Batcave
Once inside the Batcave head over to the left and into the elevator there. This leads to a cutscene with Lex Luthor and the Joker. The Joker gets his hands on Lex's new ray and using it lets out most of the villains of Gotham City.
The scene return to the Batcave with Bruce Wayne and Dick Grayson. Follow the phantom chips to the right and the computer will pop out. The Martian Manhunter will be checking in and then an emergency crops up. Interact with the computer again to learn just what is going on. Alfred will tell Bruce that the scanner is ready for use. Look to the left and down to find the red exclamation point. Hit the prompted button to scan the area and reveal the emergency. Next, place a beacon on it so it is easier to track.
Batman and Robin suit up and head on out of the Batcave to investigate the scene. Head up the road and stay on it. It will lead you directly to Arkham Asylum. Stop before the bridge and head over to the left of it. There you will find the switch to raise the bridge. Throw it, wait for it to raise up. After that, head on in.
The Maze
This gives rise to another cutscene. Catwoman is loose in the maze inside Arkham Asylum. Head into the maze and go over to the first alcove on the right. There is a fountain there. Have Robin through a Batarang at the two clear green pieces in the top left and right corners behind the fountain. This will stop the water from gushing and lower the jumping pieces.
Put the pieces together to create a pull switch. Target it with your grappling gun and move back a moment. The fountain will spin around and reveal a suit changer for Robin so he can equip the Acrobat suit.
Once in the Acrobat Suit as Robin, head over to the green mist with the deadly plants inside it. Target the socket that is in the middle on the left-hand side. Double Jump over to the Rod and jump from it to clear the gap. Head North from there and then immediately turn West and start going to the South on the thin Red Wooden Beam. Robin will balance, just make it to the part that he had to jump with his rod. Along the top of it there are 2 piles of pieces to assemble: one to the left of the socket and one to the right of the socket.