Jeremiah built the bunker/maze to protect himself from Jerome, Jeremiah was hiding in the bunker for a long time. He built it there on purpose so that it was harder to find him. it took about 6 years until the bunker / maze was finished, with security and all. But when he was told that Jerome had escaped from Arkham again, he panicked but he knew that Jerome was coming to him one day. He had also changed his name to .... so it was harder to find him. Jeremiah had arranged for Jerome to go to his proxy Ecco who would beat Jerome unconscious and when Jerome woke up he got stuck in a room that Jeremiah had made for him, with an entrance but no exit.
However, Mad Hatter and Scarecrow followed Ecco when she transported Jerome to the maze bunker. When Jonathan and Tetch tracked down the lair in the Gotham Woods, Hatter managed to hypnotize Ecco, whereon she allowed the two villains to enter Jeremiah's maze and revealed the path through Jeremiah's hiding place. While Scarecrow freed Jerome from the prison cell, Ecco and Mad Hatter proceeded to approach Jeremiah's office room, not unnoticed by all the video camera installed at the maze bunker. Mad Hatter then ordered Ecco to find Jeremiah and take him to Jerome, whilst fighting everyone who stands in her way. However, Harvey Bullock and Jim Gordon managed to defeat Ecco, while Jeremiah ran away and tried to escape on his own. When Jeremiah reached the end of the maze, he suddenly heard Jerome's voice saying "Hello, brother". Jeremiah turned around in fear to escape in the other direction, however he then stood in front of Mad Hatter and Scarecrow who had followed him, whereon he turned around once again only to be confronted by Jerome who was hiding behind a corner and now held him at gunpoint.
Gloating, Jerome said "So, how ya been? Oh, you look great! To think I used to be the handsome one, right?". While Jerome laughed, Jeremiah asked him how he found his way through the maze. Jerome responded "Oh, bro, we might not look the same anymore, but we still think the same.", whereon he poked his brother's forehead and added "Plus, you used to draw those stupid things all the time as a kid. I paid attention.". Jerome then commanded "Hat Head" to take Crane and find "Jimbo and his bearded sidekick" in order to kill them. Scarecrow and Jervis eventually ran into Gordon and Bullock who were searching for Jeremiah. When they met up, Hatter attempted to hypnotize them and told them to listen to what he has to say, but Bullock drowned him out and loudly yelled "Oh, hell no! You are not hypnotizing me again!", before he started to shout and began to ran after the two villains, causing them to flee. Jim ironically noted "That's one way to do it." before he followed them. Bullock chased Crane and Tetch through the maze, shooting at them several times during the process. Horrifed, Mad Hatter shouted "must go, must go" repeatedly while running through the corridors.
Jonathan and Jervis eventually fled back to the exit and found themselves in the same place where Jerome was still talking to his brother. While he and Crane ran past the Valeska brothers, Hatter yelled "Must go! Must go! They're after me and the Scarecrow". Jerome said "These guys just don't give up, huh?" while Jonathan and Tetch made it to the exit and left Jeremiah's maze. When Jerome heard Bullock yelling, he immediately held Jeremiah in headlock and pointed his gun at him. When Jerome threatened "Get any closer and I splatter him. I splatter bro-ski.", Gordon peeked around the corner and said "No, you won't. If you wanted him dead, you would have killed him already". Jerome then laughed for a short moment before noting "He's right. I'll see you soon". Jerome then pushed his scared brother to the side and started shooting at the two GCPD officers in a comedic way. He then ran out of the maze bunker, laughing maniacally in the process. Bullock and Gordon followed him outside but all the three villains were already gone, they had managed to escape into the nightly Gotham Forest.
A few weeks later, Ecco waits for Jim Gordon inside Jeremiah's maze with a self-perpetuating Generator which is slowly starting to overload. When Jim arrives there, she holds a gun to his head while he’s watching a video of Jeremiah posing as Jerome. During the scene where Jeremiah pretends to choke himself as Jerome, Ecco gets momentarily distracted, allowing Jim to knock her gun away and defeat her in combat. Jim then unmasks Ecco and is shocked to find out that the attacker was in fact her, just as Jeremiah was about to reveal his true face in the tape. While Jim is being distracted by Jeremiah’s reveal, Ecco wakes up and escapes, sealing Jim in the room.
- "A Dark Knight: Mandatory Brunch Meeting"
- "A Dark Knight: That's Entertainment"
- "A Dark Knight: That Old Corpse"
- "A Dark Knight: One Bad Day" (mentioned)