After the Joker gameplay, get out of the Batcave with Batman and go to the waypoint on the map.
Go to the Billboard, you can use the Detective Vision to find the exact location of the broken wall, then press the appropriate button to get through.
You will find Enigma's base.
Then go to the next waypoint and get down inside the sewer opening.
Use the Glue Granade to stop the gas on the opened pipes.
Go down to the Infirmary, through the Broken Wall, and continue forward.
Find the locked door to the morgue, hack it and go inside.
There will be a crime scene there, scan the body.
Then walk up to the computer and use it.
After that, get out of the PD, and go to the waypoint on the map.
Inside Bane's base, at the sewer, use the Glue Granade.
Get on the Floating Platform.
Then like before, use the rings to pull yourself forward.
After the cutscene, head back to the Batcave.
Follow the waypoint, while Batman is programming the Batwing.