John was still snickering about practically everything when Harley and Wilkins pulled into the underground parking garage. He'd mutter something to himself and burst into another fit of mirth, the joke known only to himself.

Harley didn't know what to think. She was glad his fears weren't holding him down any longer, but she couldn't tell if the practically uncontrollable laughter in response to every thought in his mind was any better. She wondered if he'd simply exchanged one problem for another, but she thought this one was much nicer.

Wilkins turned off the engine and climbed out, hurrying around to help get John out of the back seat. Harley left the car and pressed the button for the elevator. Once the metal box was on the way down, she took John's free arm and draped it around her shoulder, ignoring the green chemicals transferring to her clothing.

"My apartment is on three," Wilkins explained. Once all three of them were in the elevator, Harley pushed the button for the indicated floor.

Either no one was around or no one wanted to come out their door as Harley and Wilkins carried John down the hallway. Phosphorescent green still covered him, and he giggled with little to no visible provocation.

The apartment was like many in Gotham, terrible. What remained of the wallpaper was badly faded, hanging off the wall like strips of animal flesh on a carcass left to the vultures. The plaster under the wallpaper was little better, crumbling to a fine powder and exposing the wood structure underneath. The carpet, burnt and stained by former residents, was a drab brown the color of dirt. Patches were missing from the carpet where it had been chewed by rodents. A ceiling fan turned slowly, doing more to stir the dust than anything else.

The furniture was in mildly better shape, but rats had left teeth marks on most of the edges. A sofa and mismatched chairs of black and brown were wedged into the small living room around a beat up coffee table of dented pine.

Harley and Wilkins laid John on the sofa before Wilkins went to retrieve a few items from his room down the hall. Staying beside John, Harley held his hand. Using the edge of her sleeve, she brushed away some of the gelled chemical from his hair, only to find the strands underneath maintaining the color. She rubbed the hair between her fingers and thumb, trying to remove the coloring, but it refused to be dislodged.

"It looks like the chemicals changed your hair to green," Harley commented.

"Going green is the thing to do these days," he joked. "Who cares anyway? It's only hair."

***

"Come on," Harley growled. She leaned against the wall with one hand, drumming her fingers on the wall while waiting for Wilkins to finish the testing he'd been working on for almost two hours.

"Alright," Wilkins replied, leaning back from his microscope. "I just wanted to recheck my findings to be sure."

"What is it?" Harley asked, pushing away from the wall and staring at him intensely.

"After comparing the fear neutralizing gas and the liquid laughter, I believe the mixture of the two has created an unexpected mutation of the genetic code within his cells," Wilkins explained.

"In English, please," Harley responded.

"The combination changed him," Wilkins clarified.

"To what degree, and what do we do about it?" Harley pressed.

"The mix affects his muscle structure," Wilkins went on. "Although he still looks slim, he'll be much stronger and more resilient than before."

"That sounds good," Harley accepted.

"It has also affected his hair color," he told her.

"Noticed that," she admitted. "The duration of the liquid was very short. How about the mix?"

"Unfortunately, the mutation seems to be permanent," Wilkins admitted. "The intensity of his susceptibility to humor will lessen in the next few days, but it won't ever abate entirely."

His gaze dropped to the floor as his shoulders slumped. His mouth opened to say more, but no words came out.

"What else?" Harley prompted. Wilkins looked up and met her eyes.

"The muscles on his face contorted slightly as the mutation ran its course," Wilkins said, hesitating every few words as if difficult to say them. "I've been monitoring their progress, and his face is going to be different."

"How different?" Harley asked.

"See for yourself," Wilkins suggested. He took John by the shoulder and gently rolled him over on the sofa where he'd been lying so John could look at the two of them. When he grinned at Harley, it startled her as the smile was much wider than before, almost dividing his face in half and letting his gleaming teeth be much more visible.

"Something wrong?" John asked.

"It's a matter of opinion," Wilkins answered, handing him a small mirror he'd retrieved from the bathroom.

John looked at his new face and hair in the mirror, at first jerking back from the leering grin of his reflection. Turning his head slightly to one side and then the other, he considered it before the smile widened even further.

"For a guy who's supposed to find the funny side of things, I now have the face for it," he told Harley while snickering.

"At least you don't seem to mind," Harley observed.

"Never had a mind, so why should I mind," John replied with a giggle. "Seeing as I have a new face and personality, how about a new name?"

"What would you like?" Harley inquired.

"I think it should go with Harley Quinn," he answered. "Something fun to match my smiling face."

Harley looked around the room and found a triangular bookshelf in the corner of the room. Puzzles and board games were stacked on its narrow shelves, and she noticed a pack of playing cards. Harley smiled as she turned back toward John.

"I've got an idea, Mr. J," she told him. "What about the name Joker?"

Harley retrieved the pack, pulled out the two cards at the front of the deck, and handed them over. The grinning face depicted on the card could've been a lunatic, and John smiled in unison with his new namesake.

"I like it," he told her. Sitting up, he tossed the card on the coffee table. "Let's go have some fun."