I will say this, there's a part at the end that doesn't really match the song, but that part just flowed out through my fingers.
Joker was doing his usual thing, threatening Gotham, but instead of drawing out Batman, he drew out Red Hood.
"So, you're the new Red Hood, I've heard about you." Joker said, shooting one of his hostages.
"Oh, you know me more than you think, laughing boy." Red Hood said, glaring at Joker.
"I'm sorry, that implies that we've met before." Joker said, then his laugh came out.
"Oh, we have, but now, it's time for you to pay for your crimes over the years." Red Hood said as he lunged at Joker to stop him from killing another hostage, and restrained him quickly.
"You seriously think I'll stay in Arkham?" Joker said as he turned around after Red Hood finished.
"Who said anything about Arkham, it's time you got what was really coming to you." The deadly vigilante said, and with that he started dragging the Clowned Prince of Crime away.
It was several hours later, and Batman was befuddled at the fact that Joker just disappeared during one of his crimes, and the only clue was a piece of cloth. The Dark Knight and his former protégé, Flamebird were checking out everything. After her encounter with her 'little brother', Flamebird had told Batman, and then she did something that she was still getting used to doing.
The fire controller closed her eyes, and held her hands chest lever. She always knew that everyone had a different heat signature, but she only started reading for them afterward about three years ago. When she recognized two separate heat signatures, she didn't seem all that shocked.
"Batman, it was Jason." Was all Flamebird said, and this made Batman's eyes narrow. "But why… oh no, he wouldn't, would he."
"The way you told me Jason was acting, I think now he is in the state of mind to actually kill Joker. I think I have an idea of where he took him, let's go." Batman said as he stopped what he was doing and started to leave the scene.
Flamebird didn't know what was going to happen, but she followed her ex-mentor in hopes that they would stop Jason from making a terrible mistake.
The whole time Joker was held captive, Red Hood had tortured him, but the one thing the deadly vigilante favored was a crowbar.
"So, you ready to laugh, it's about time you did." Red Hood said.
Joker tried but all that came was a low laugh, nothing like his usual one.
"Sounds like you have a collapsed lung; that always impedes the auditory. " Red Hood said with what sound like a laugh in his own speech.
Joker tried to free himself from the chair he had been tied too since hour two of his captivity, but it didn't work as he was still there. The Clowned Prince of Crime had several cuts from knives and even a scalpel. The villain couldn't help but think about what Red Hood said about them knowing each other, and he had run through all the people he 'knew' in his head (when he could actually think) and came up with nothing.
"Guess it's time to reveal who I am to you, scum." Red Hood said as he came back with his guns held out.
He then placed them in their holsters and reached up to his helmet. Once it was removed Joker's eyes widened when he noticed it was the boy he 'thought' he killed. Red Hood just smiled as he saw the expression on the maniac's face. The vigilante then walked up to his captive and knelt down.
"So, how do you like this little reunion?" Red Hood stated.
"I…I killed you." Joker said.
"Well thank the person that hired you for that little job for my being here." Red Hood stated.
Joker didn't have time to respond when his captor reached for his guns. Just as Red Hood pointed one at Joker's head for the final blow, the other went to the window when a noise was heard outside. Before either occupant could react, a fireball came crashing through the window and surrounded Red Hood. Three seconds later, Batman and Flamebird came in through the same window.
"So, it took some time but you finally found me. You're just in time to see me finish this whole thing." Red Hood stated.
"Robin, this has to end, and it will with him going away." Batman said, hoping to get through to the kid he knew.
"No, you couldn't do it, even after he took me away from you, sure you had Rei and Dickie-bird, but for the first time I had the right kind of parent. Then Joker blew me up and all you did was put him in a body cast then throw him in jail." Red Hood said as he pointed one gun back at Joker and the other was pointed at his former mentor and the girl of his dreams.
The deadly vigilante glared then turned to face Joker. With a smirk on his face, Red Hood pulled the trigger on the gun pointed at his captive, but the moment the bullet left the gun, Flamebird put up a fire shield around Joker. The bullet was melted as soon as it hit the shield, but what she didn't expect was that Joker would get close enough to the flames to burn the rope holding him.
Once her fire shield died down, Flamebird was ready to fight Jason, but Joker jumped out of the chair and attacked Red Hood instead. The Clowned Prince was able to wrestle one gun from Red Hood, and quickly turned it on Flamebird, the bullet hit dangerously close to her heart. After realizing that Batman would be pissed with him, Joker took off and was laughing.
Flamebird fell to the floor, but she was caught by Jason who manage to beat Batman to it. Now he saw what Joker was capable of, but he also couldn't kill him, thinking that this same mistake might happen.
With that thought in mind, Jason picked up his helmet and vanished the way a Bat should.
Worried about Flamebird, don't be, as there is kind of a sequel one shot coming that will explain things after the end of this.