A/N: I've been looking into the current DC Multiverse and a lot of it sounds really interesting. I did not completely understand the plot to the Multiversity comics but I liked the concepts behind a lot of the alternate Earths and wanted to do something with them. So that's how we got here. Originally I had Superman in mind to be the protagonist. Then I changed it to Batman, then Supergirl, then Joker, and finally decided on Harley Quinn to be the lead character. Specifically, the DCAU Harley Quinn since that's my favourite version of the character (Although I do like some of her other interpretations). I feel like I might get certain details about the Earths in this story wrong (Because like I said, Multiversity was a little confusing) but I'm gonna try my best anyway.

"Me?! Give you equal credit!? Ha! I don't think so!" the Joker marched towards Harley with a look on his face that seemed part angry, part amused.

"I just feel like ya take credit for too much stuff... We're a team..." Harley backed herself up against the cold brick wall of the abandoned comedy club her and the Joker were living out of. "I do a lotta stuff around here is all I'm saying… Maybe next time we burst into a bank or attack one of those charity gala's you could announce both of us instead of just you. That's a good start, right?"

The Joker broke out into his signature hyenalike laughter and put a hand against the wall Harley was backed into. "Oh Harley, it's so cute that you think we're equals. But really now, I'm Batsy's greatest rival and you're my ditzy sidekick. How do those even compare?" he paused for a moment to let Harley take in everything he'd said. "Now, tell me you're sorry."

"I'm sorry Puddin'..." Harley tried pushing herself into the wall some more.

"Good. Since I'm a charitable man I'm going to let you sleep on the couch tonight." the Joker turned himself around walked away from Harley.

Harley scrambled after the Joker. "The couch? But Mr. J, I like sleepin' with you. You keep me warm and the couch is all dirty and-" she stopped herself from speaking when she saw the Joker turn around and glare at her. "And I'll sleep on the couch like ya said..."

"That's a good girl." Joker looked away again, smiling. "Stop talking to that weed-lady, by the way. I think she's the one putting all this nonsense about us being equal in your head."

"But I like her." by this point Harley was looking down at the floor, too ashamed to look at Joker in the eye.

The Joker twirled back around again. "I am sick of you talking back to me. Your couch privileges are revoked too!"

"But Puddin'-"

"Now your floor-sleeping privileges are revoked!"

"Mr. J, can I please-"

"And now I want you out of here entirely!"

The next thing she knew, the Joker was pushing Harley towards the back of the comedy club and out the exit doors.

"C'mon Puddin, it's cold out there and it looks like it's gonna rain!" Harley protested.

"I don't care! I just want some peace and quiet in here for once!" Joker yelled back. With one final shove, Joker pushed Harley out of their hideout and into the back alley.

Turning herself over, Harley looked up into the pale face of the Joker. "Can I at least take Bud and Lou with me? They're gonna miss their mommy."

"No. Frankly Harley, the hyenas make better company than you sometimes." Joker slammed the door shut, leaving Harley Quinn alone in the dirty alleyway.

Harley sighed and picked herself up from the ground. "I'll show him… I'm gonna find a way to make him jealous… Somehow." she went down the alley towards the sidewalk. "Should probably go see Red. Then I can get some sleep first."

The trek from the East Gotham comedy club Harley and Joker called home to the abandoned house on the outskirts of the city that Poison Ivy resided in was a long and unpleasant one. Despite the clouds threatening it, there was no rain that night. The lack of rain didn't improve Harley's mood though. By the time Harley was knocking on Ivy's door, she was cold and miserable.

After repeatedly tapping at the door for almost twenty seconds, it opened up with Poison Ivy on the other side. Ivy had gotten used to Harley unexpectedly showing up in the late hours of the night and had very little reaction to seeing her on her doorstep.

"Hey there, Red. Mind if I stay over for a little while? Me 'n Mr. J had a teensy little argument." Harley made herself smile at Ivy.

"Sure, come on in. I'll make you some tea; grew the leaves myself." Ivy stepped to the side to make room in the entrance for Harley.

"That sounds great. Thanks." Harley entered Ivy's home and made her way over to the dining room.

Harley quietly sat at the dinner table thinking about where exactly her night went wrong while Ivy went to work brewing some tea. Eventually, Poison Ivy sat down in front of Harley and placed two mugs of warm herbal tea in front of them.

"That should warm you up." Ivy sipped on the tea while Harley blew on her beverage to cool it off. "So what happened this time, Harley?"

"He didn't like me sayin' that we should get equal credit in his Batman killing schemes." Harley explained. "Then he said he was kickin' me outta bed and it kinda just got worse from there." deeming her tea cool enough, Harley took a gulp of it. It burned her mouth a little, but after being exposed to the night air for so long it was almost a relief.

"I know it's a lost cause by this point but you need to start thinking of breaking things off with him." said Ivy. "I enjoy your spontaneous visits but I can't watch something so unhealthy go on."

"It's a little unhealthy, but we make it work. He's big sweetheart once you've lived with him for long enough. Just havin' an off night this time, really." Harley insisted.

"You know Harley, some people say that there's a perfect soulmate for everyone out there in the universe." Ivy remarked. "I personally don't believe in that emotional human garbage but I think you might want to look for yours a little more. Just see if there's anyone else out there."

"I don't need ta search, I already found him." Harley took another large sip of tea.

Ivy exhaled in frustration. "I'm too tired to talk about this… It makes me upset. Let's just finish the tea and get you to bed. Where do you want to sleep? There's the couch, the recliner, my bed, and the guest bed. You're going to have to clear some stuff out of the guest room if you want to use that one though."

"I'll take the guest room, I'm sure it can't be too much work to clean it out."

After the last drops of tea had been drained away, Harley went over to Ivy's guest room which apparently had been converted into some kind of storage space since she was last there. She went straight to work clearing out anything blocking the bed off from her.

Harley picked up a large box of chemistry tools off the bed as Ivy came into the room to check on her.

"Hey there Harley, I brought you some sleep clothes." Ivy went over the bed and placed down an oversized T-shirt and a pair of sweatshorts.

"Thanks Red. I almost forgot about that." Harley placed the box down on the floor. "Good thing you remembered. This jester getup isn't too comfy to sleep in. Just a few more boxes and I should be ready for some shuteye."

"Be careful when you're putting this stuff away." Ivy advised. "There's some dangerous stuff in here."

"Like what?"

"I've been working on a new hallucinogenic poison. I know we're both immune, but it'll just be a real pain to clean up if it spills. So if you need help, let me know."

"Nah, I'll be fine." Harley made a dismissive gesture with her hand. "Thanks for offering."

"Well, I'm just down the hall if you need me." Ivy turned away and disappeared out through the door frame.

With Ivy gone, Harley went back to the task of clearing the bag, picking up another box. This one was mostly filled with books and papers but there was a vial of brown liquid with a cap on it resting on one of the books. However, Harley failed to notice that as she picked up the box.

"Where do I put you?" Harley looked around the room in search of a suitable place for the box. Before she had a chance to put down the box, the vial of unknown liquid rolled off its perch and hit the floor. The vial shattered, spilling its contents everywhere. Harley dropped the box she had been carrying in surprise.

"She told me this would happen…" Harley grumbled. "I'll get it in the morning. 'Least I won't be having any hallucinations." she bent down to pick up the box but stopped before she could even touch it when she heard a voice from behind her.

"Excuse me, do you need some help?" a squeaky voice made itself known from behind Harley.

"Yeah Red, I actually-" Harley froze when she realized that the voice behind her did not belong to Poison Ivy. Slowly, she turned herself around and saw someone, or perhaps something, she never would quite be able to unsee.

It was a short man, no taller than a child, dressed up in what appeared to be some kind of home-stitched Batman costume. A poorly made Batman costume at that. The ears drooped, the boots and gloves were too big, and the bat-symbol on the chest was horribly misshapen. The person appeared to be floating in the cloud of fumes that had been released into the room. Harley stared at the being in absolute dumbstruck confusion as it spoke some more.

"My name is Bat-Mite! Fifth-dimensional imp and Batman's biggest fan!" the creature announced.

Harley's brain raced to figure out what the hell she was seeing. Her first thought was that somehow the formula Ivy concocted was potent enough to override her immunity and she was having some kind of vivid hallucination. Ignoring the apparent imp, Harley dashed out of the room and down the hall.

"Red! I spilled your pollen and it's messin' with my brain! Can you please help me?!" Harley pushed open the door only to freeze up upon entry. Inside the room Ivy was stuck in place, watering a bedside flower pot. She didn't appear to be moving or even breathing. The water coming from the watering can was suspended in mid-pour as well. And floating in front of her friend was the thing from her bedroom.

"I feel like we got off on the wrong foot." the entity calling itself Bat-Mite remarked. "Let's start over. Hello, my name is Bat-Mite. I've travelled through time and space to find you. Didn't take as long as you'd think."

"Are you real? What did ya do to Ivy?" asked Harley.

"I'm just as real as you are, Harley. And don't worry about her, I just paused her. I thought we could talk." Bat-Mite said.

"I don't understand, what's goin' on?" Harley grew increasingly confused and worried about the situation.

"You see, I love all things Batman. And that includes his most fearsome foes, like you." explained Bat-Mite. "I go around and spy on his greatest adventures. And sometimes I show up and mess with him. Spice up his life. But he doesn't like that."

Harley stared at the imp in front of her with her mouth agape. She'd seen some pretty bizarre stuff before but this was beginning to push her limits. She stayed silent in hopes that something Bat-Mite said would make sense.

"I've decided I wanted to mess with someone new. The Batmen of the Multiverse are getting too good at countering my trickery." Bat-Mite went on. "You and the Joker are having troubles, right Harley?"

"Every couple has problems." Harley replied, almost automatically

"Pay attention Harley, this is where most people get confused. Your reality isn't the only one that exists. There are fifty-two universes out there and you're living in just one of them. So, I'm willing to give you a guided tour of the Multiverse so you can see the different versions of your very own Mr. J. How does that sound?"

By this point, Harley felt like she had some understanding of what was going on and she tried to respond. "Okay… Let's say you ain't some figment of my imagination. Why are you doing this? Why me?"

"Well, I'm bored with bothering Batman so I thought I'd try having adventures with some of his villains." Bat-Mite said. "And as for you specifically, Harley Quinn is one of Batman's most popular enemies. I thought it would be fun."

"Popular? I'm a wanted criminal." Harley pointed out.

"Well, not popular here. You wouldn't believe me if I explained it." Bat-Mite told her. "Anyway, you are what I like the call Harley Quinn Prime. The first known instance of Harleen Quinzel existing in the Multiverse was on this very Earth. So, I figured you'd be the best Harley to take on a little trip."

Harley observed Bat-Mite, looking over him with much scrutiny. "Okay… This is real… I ain't creative enough to think up any of this stuff myself."

"Good. So would you like to go on an adventure? See the Batmen and Jokers of the Multiverse? Maybe even the Harley Quinns of the Multiverse?"

"No way, I don't want any of that. I just want you to go back whatever crazy world you're from-"

"The fifth dimension."

"- Go back to that place and leave me alone. Just lemme live my life, it's exciting enough without any alternate dimensions or whatever you've been saying."

"Well, that's too bad. You see, I'm one of the most powerful beings in the Multiverse. We're having this adventure regardless of what you say." Bat-Mite snapped his fingers.

"Hold on-" Harley's words were cut off when both she and Bat-Mite were engulfed in a cloud of smoke. As the smoke surrounded her, Harley realized that things were somehow going to get even stranger than they already were.

A/N: The actual dimension-hopping shall commence next chapter. Little note, future chapters may have Bat-Mite make reference to Earth-12 as Harley's home universe. I checked the DC wiki and the Earth that's supposed to be the DCAU is called Earth-12. Anyway, this chapter was a bit short but it was just the prologue. The rest are intended to be longer. The first Earth Harley will be visiting is Earth-0. AKA, the current main DCU. This story should be updated weekly but it may take a bit longer depending on certain factors. So if you liked this prologue, keep an eye out for updates.