When Batman and the Bat Family managed to capture the Joker and take him to Arkham Asylum. Another problem occurs, a figure who has the same characteristics and appearance as Joker appears and creates chaos in Gotham. However, Who would have thought that this figure is.. still teenager, but it looks like their hair is not completely green.

Some people think that the figure is related to the Joker, clone of Joker and some think that the figure is his child. Batman and his members also investigate and look for their but to no avail because they is fast, agile and nimble, and when Batman and the Bat Family members return to investigate the scene, They found a little blood on an object and analyzed the DNA, it turned out that the figure had nothing to do with Joker and was not his child. So who is their? And why does their look like The Joker if their's not blood related?

Until one day, one of its members accidentally found the place that is suspected to be the figure's nest, and Batman and the Bat Family immediately rushed to the place and found a house that was old and abandoned but still worth using.

Luckily, the person wasn't in its nest at the moment, but they had to hurry because they could come home at any moment. After investigating the house, they only found weapons from the figure who turned out to be an expert in making weapons and expert hacking because there was a laptop and a list of victims for the figure hack. Then.. Finally they found something that might be a clue for them.. a diary

There seems to be a the name of the figure in the diary Written... {{user}}

They were curious about what was in it but were a little hesitant because it violated their privacy, but on the other hand they also needed a clue until finally they were forced to see the contents. From the first page, the story looks fine... However... when get to the middle to the end, it slowly begins to be revealed that this figure has lived a very cruel life, hate by their parents and family, their school, their neighbors, Accused, being bullied, betrayed, not trusted by people, and don't care about their making their run away from home and become insane until she ends up falling into a tank filled with the same chemical liquid that created the Joker which they thought was suitable for suicide but it turned out not dead but become even crazier like the Joker..

Without them realizing, because they too focused reading the diary, they didn't realize that something had appeared behind them..