The Joker had stolen a big gun from Star Labs which he planned to use to kill his target, Batman. The break-in at Star Labs alerted Flash who, upon seeing who it was, quickly informed the Bat. Batman left his girls in charge of Gotham while he and the boys were away. When they got to Central City the Bats went to the secret hideout where the Bat-family always meets the Flash family.
"You're late," Batman states as soon as Flash stops.
"Oh, come on Bats! You guys move faster than people would think. Are you sure you guys aren't speedsters?" Barry says having known that he was going to be late.
"Wallman, you ready to kick some butt?" Dick asks.
"You know it," Wally cheers.
"If you 2 are done wasting time we've got somewhere to be," Jason says already on his bike ready to go.
"Way ahead of you Jaybird," Dick yells over the engine of his bike.
"I would listen to the plan first," Tim shouts over to his older brothers.
"We know that Little Red," Jason yells back.
"Plan Delta," Batman tells his 3 graduated Robins.
"What about Wally and Bart?" Tim asks.
"They are using Plan Beta," Flash says knowing the Bats will understand.
"What does that mean?" Bart asks genuinely confused.
"It means we are doing border patrol on the fight till the others arrive or 5 minutes after Batman and Robin show up," Wally explains.
"We need to get going Father, he is moving in 30 minutes," Damian calls from the Batmobile.
"He's right, we need to go," Dick yells ready to take off. The Bats are ready to go and Flash takes off with Kid Flash and Impulse on his tail. Seconds later the Bats are off with Nightwing, Red Hood, and Red Robin going to the other side of the city. They start the plan and Red Hood takes off and starts shooting blanks at his brothers. They follow 30 seconds later 'dodging' the bullets.
"You have 5 minutes starting now," Robin states as the Batmobile pulls to a stop.
"Copy that," Tim responds while taking a different route than his brothers to 'block' Red Hood from escaping. This is the signal to them that the timer has started. They start to head towards the fight still 'fighting'. When the 5 minutes end all 3 glide down from the roof of a nearby building and join the fight.
"Aw, come on! Though I should have seen that coming," Joker complains. He motions for one of his cronies to get the gun.
"What is so special about this thing anyway?" Jason asks Dick quietly.
"It is built to jump dimensions," Dick whispers back.
They are almost done with the fight within seconds. Then the Joker's back up arrives. He starts laughing hysterically and says, "Oh, wait, I did expect it and planned for it."
"Oh shoot," KF says.
The gun was fully charged and Joker points it at them and says, "Oh, I can take out all of you in one go. Let's do it. Bye, bye Bats and speedsters." With that, he pulls the trigger. The heroes blackout from the impact. When they wake up they are all over New York in a different dimension.