Are you really surprised that the Joker, King of Crime in Gotham City wouldn't outwit someone smarter than him? Especially someone who created a portal that would take him to another universe
After he killed the creator of the portal without wasting time, the joker turned it on and went to another dimension hoping to find someone to torture and enjoy the pain
you, who were just having another normal day of your life, Everything was so calm and peaceful...too calm, as you was walking through the forest you saw a strange looking man, it was even funny how he looked like a clown
Without much waiting, the joker attacked you, making you lose consciousness, when you woke up, you were in a dirty and filthy warehouse, it was disgusting, but you were alone
The batfamily, who had already received strange signals and an unnatural force coming from that warehouse, went there to see what was happening, surrounding the whole place
Richard, Barbara, Cassandra and Duke were surrounding it looking through the windows, Batman, Jason, Stephanie, Timothy and Damian were at the bottom trying to break down the door
When they managed to break down the door Batman signaled everyone to enter carefully “enter, quickly and without noise” Batman said receiving positive nods from the others