Hey everybody! This is the start of a new multi-chapter fic set in the 2012 TMNT series! Ralyena Starrling and I hope you will enjoy it!

Disclaimer: I own nothing!


-Chapter 1-

It had been about a full year since the Kraang invasion had been halted in it's tracks, as well as Shredder and his Foot clan had been knocked down. April and Mr. O'Neil had moved back to their Brooklyn Brownstone but still kept close to the turtles. Since then, Donnie still had yet to find a cure for Timothy, but he worked diligently and wasn't about to give up.

Unfortunately, the same applied to Dogpound and Fishface, who both still caused trouble around town just to stir up trouble. Tonight was no different when April called saying that a video of the large dog humanoid and fish man with metal legs was posted.

"They're attacking a cargo shipment for medical supplies at the pier! You have to hurry!" April exclaimed over the phone.

"Don't worry, April. We're on our way," Donnie replied, before hanging up his shell-cell and running out of his lab calling for his brother's to scramble.

In record time, the four turtles had packed up their gear, climbed into the Shell Raiser, and zoomed off to the pier. As they neared the pier, Raphael climbed up to the roof and manned the trash cannon. With precision aiming, he set the target reticule for Fishface's face and pulled the trigger. A cannonball made of compressed refuse found in the New York City sewers shot out of the cannon. It would have been a clean hit had Dogpound not smelled the incoming projectile and pushed his partner out of the way.

"It's the turtles!" he growled, getting back to his feet and grabbing a nearby cargo crate before lodging it at the Shell Raiser. The subway car turned truck swerved to the left, effectively dodging the crate, before coming to a halt and unloading it's payload of four mutant turtle heroes.

"Gettin' real sick of you two," Raphael growled.

"Time to flush the fish down the toilet, and send the dog to the pound!" Michelangelo said by way of agreement before chuckling and saying, "Get it? 'Dog to the pound'? Cause his name is Dogpound?"

Fishface chuckled at this while Dogpound glared at Michelangelo with murder in his eyes. With a single snarl, Dogpound went down on all fours and rushed the turtles.

Donnie was the first to strike, and whacked the Akita humanoid in the face to force him back. Mikey assisted, and while they fought with Dogpound, Leo and Raph fought with Fishface.

"Attacking a shipment of medical supplies, Fishface? I'd say you couldn't get any lower, but considering where fish come from, that'd be redundant," Leo stated as he blocked a kick from one of the metallic legs.

"Business, turtles. We were specially hired by a contact who wanted something hidden on this ship. All Rich-Boy and I were doing was looking for it," Fishface explained.

"Oh yeah? What's hidden there?" Raph asked.

"Not one damn thing that concerns you!" Fishface stated, spinning his other leg to kick Raph in the face.

Mikey and Donnie, meanwhile, were managing to keep Dogpound on the ropes. The Akita humanoid was looking as if he was getting tired, which greatly helped in throwing him off his game. But when Dogpound smacked the two away from him he managed to pin each of the younger brothers down with a single hand; Michelangelo with his left, and Donatello with his right.

All of a sudden, an inhuman roar ripped through the air, causing both mutant turtle, dog, and fish alike to freeze. "GET AWAY FROM MY FRIENDS!" a voice full of fury cried before a large scaly mass tackled Dogpound, effectively freeing Donnie and Mikey from his grasp.

Michelangelo dusted himself off and looked towards the nearby scuffle and froze. Dark green scales, long, thick snout, webbed hands and feet tipped with razor sharp claws, and a long, powerful tail; it could only be...

"Leatherhead!" Mikey cried out in joy at seeing his long lost friend.

The mutant alligator looked up briefly, just long enough for Mikey to see that Leatherhead's inner eyelids were not covering his eyes, meaning that Leatherhead was in full control of his faculties! And still, he fought with such fury...Mikey wasn't sure what to think.

Deciding to leave his partner to his fate, Fishface did a one-eighty and ran. However, he didn't get far.

"GOONGALA!" a young male voiced cried before a solitary figure fell from the sky and, with a down-stroke, hit the top of Fishface's head with a hockey goalie stick.

Leonardo's and Raphael's eyes widened in surprise at the surprise attack, and even more at the person responsible.

The man was about 6'2", raven black hair that didn't lay flat, and reached just above his shoulders. He had a medium build; svelte, like an Olympic runner. He wore a black sleeveless tee with a white insignia of an upturned fist with it's middle finger sticking out right in the center, faded blue jeans with holes in the knees, and tears along the thighs and calves, and black tennis shoes. Strapped to his back was a golf caddy filled with various sports equipment: a baseball bat, a cricket bat, a tennis racket, a golf club, a regular hockey stick, and, oddly enough, a sledgehammer! But nothing about his apparel was nearly as odd as the hockey mask on his face. The empty eye holes, nose holes, and the slits along the mouth gave it a skull-like appearance.

All in all, the teen looked very intimidating.

"Well, if it isn't Rover and Nemo. We've been looking for you two for a long time," said the young masked man.

"You're not getting away this time," Leatherhead said with a growl.

"Oh damn. Not these two again. Time to go, street rat," Dogpound said and ran off.

"For once I agree with you, rich boy," Fishface replied and ran after his partner in crime.

"No you don't! Mikey, help me with this chain!" Donnie said as he grabbed a large chain and, with Mikey's help, managed to lasso it around Dogpound's ankle.
While the chain was able to pull back the Akita humanoid a bit, Fishface used his fangs to bite through the chain. This made the younger turtles fall back after losing their leverage. And soon the villains were gone.

"Come on, LH, we gotta chase down those bozzo's!" the strange teen cried as he made to chase after the two mutants. However, Leatherhead stopped him by standing in his path.

"No, we must secure the shipment. They did not find it," Leatherhead replied to his young accomplice. Turning his head to give the turtles (Michelangelo in particular) a sidelong glace he added, "I must also tend to a...reunion."

The young man growled in frustration, pulling off his mask as he did so. "Fine, go to your stupid mutant reptile convention. I'll find the shipment." He then walked off to where Dogpound and Fishface had been searching through some cargo crates.

Leatherhead sighed and walked over to the turtles, who were looking at him with surprise. That is, except for Michelangelo. Leatherhead could clearly see the joy and happiness in the youngest turtle's eyes at seeing him again.

"Michelangelo," Leatherhead said with a smile.

"Leatherhead!" Mikey exclaimed as he ran to his best friend, and jumping into his outstretched arms. "Dude! How'd you manage to get back? Last we saw, you got sent back to Dimension X with that giant statue guy!"

Leatherhead sighed and replied, "Traag, yes. I do not remember much of what happened when I first arrived in Dimension X. I think I may have lost myself completely to the rage within me. All I can see are blurry images of violence, destruction, and...death." Leatherhead hung his head in shame; he still felt an overwhelming amount of guilt for what he'd done.

Mikey gave a sympathetic look at hearing this. He understood why the giant alligator would feel so guilty. Despite his rough looks, Leatherhead was a very sensitive and gentle soul. And killing was not something he ever wanted to do unless he had to.

"Oh Leatherhead, it wasn't your fault. You just can't control it," Mikey said and patted the large hand comfortingly.

"I know, but I just wish that it wouldn't happen so often," Leatherhead said softly.

"Well, now that you're back, I can help you control your temper a bit more," Mikey said and hugged his fellow reptile. Leatherhead was a bit startled at first, but then he hugged Mikey back.

At this point Leo then turned to the masked human. "And just who are you? You sure don't seem like an average Joe." Leo pointed out.

"The name's Casey Jones," Casey said, looking up from his search. "And no, I ain't some average Joe. I'm the best damn vigilante in the city."

Leo raised a brow and said, "Really? If you're the best, then how come none of us have heard of you?"

"Actually, I think we may have," Donatello said. "On the police scanners, 'the Sports Bandit'?"

Casey grinned and replied, "That's me! Found my calling when I realized that beatin' up crooks was a way better way to get my anger under control than electro-shock therapy!" At this, Casey's grin turned slightly manic before returning to normal.

This caused Leonardo, Donatello, and Raphael to look at him with a touch of concern and fear. Casey, however, never noticed because he'd returned to searching through the cargo crates.

"Okay...you said something about Xever and Bradford not finding something. What was it?" Leo asked.

"A prehistoric fossil that someone hired them to obtain. We don't know what it is, but if their client can revive it, it will pose a grave threat," Leatherhead explained.

"So that's why you came to stop them," Donnie said in understanding.

"That's right. For the last year or so these guys have been attacking these ships that belong to the man who also owns the fossil. He hid it on one of his ships, but so far it hasn't been found. And we want to keep it that way," Casey explained, not turning from his search.

"Alright, we can understand that. Now that leaves the question of how you two know each other." Leo said.

By this point, Casey had looked through all the cargo crates at the pier. Growling in frustration he said, "The fossil isn't here, LH! What now?"

After a moment Leatherhead replied, "Then he hasn't tried to ship it yet; perhaps waiting for Dogpound and Fishface to give up." He then turned to the turtles and asked, "I do not wish to impose upon you and your sensei, but could my friend and I use your lair as a base of operations?"

Before Leonardo could say anything, Michelangelo jumped up and exclaimed, "Of course!" much to his brother's chagrin.

Leatherhead, of course, of pleased. And so with Michelangelo leading the charge, the six returned to the sewer.

-MLH-

Back at the turtles lair, the turtles, Leatherhead, Casey, and Splinter were all sitting on the couches in front of the television. Splinter had prepared tea for everyone, to help ease any tension as Leatherhead began to weave his tale.

"As I said before, I do not remember much of my time in Dimension X; just as well, for I do not wish to remember any of it. But I do remember chasing down a unit of Kraang, and then streaks of purple energy began to swim around me. I blinked my eyes and found myself back on Earth. At first, I thought it was all an illusion created by the Kraang, and then I wondered if my own mind had conjured the image to protect me from the pain." Leatherhead's whole body drooped in sorrow as he made the trip down memory lane.

Michelangelo, sensing that his friend needed comfort, moved from his spot on the couch occupied by his father and brothers, and crawled into Leatherhead's lap. He then wrapped his arms around the mutant alligator's mid-section and gave him a gentle squeeze.

Leatherhead smiled in gratitude and wrapped his arms protectively around Mikey. The resulting scene raised a number of eyebrows, but no one said anything.

"Is there anything else you can remember about that day?" Donatello asked. "Did you see or feel anything unusual just before or just after returning to Earth?"

Leatherhead made a rumbling, "Hmm," sound, tilting his head slightly in thought. All of a sudden, his eyes went wide, causing Splinter and the turtles (except for Mikey) to tense up. "Of course! That was the day the Technodrome was to be teleported to Earth!"

Donatello's eyes went wide as a theory began to form in his head, like links in a chain snapping together one after the other. "Of course!" he exclaimed.

"Got something to share with the class there?" Casey asked with a smirk.

"When Leo smashed the power crystal, and the portal collapsed, a high-level quantum flux must have occurred. Anything quantum-linked to Earth would have been pulled back to where it belonged," Donatello explained.

Everyone looked at Donatello as though he'd grown a second head.

Donatello sighed, rolled his eyes, and explained, "Think of it as an invisible string of energy tethering us to this dimension, which explains why the Kraang needed April's energy. By pure coincidence, her quantum-link to this dimension was the strongest of anything on this planet."

Accepting this explanation, Leonardo then asked, "Okay, so why didn't the Technodrome get pulled back to Dimension X?"

Donatello took on a thinking pose before snapping his fingers and replying, "The quantum flux must have been uni-directional. Had the power crystals at both ends been destroyed at the exact same time, it's probable that the flux would have been omni-directional."

"So basically breaking the alien crystal-thing brought you back?" Raph asked.

"That's pretty much it, yes," Leatherhead confirmed.

"Well it's great to have you back Leatherhead. Now we can go back and catch up on things. And perhaps maybe we can find out who this secret client is that hired Fishface and Dogpound to find this fossil," Leo said.

"Yeah! And when we get back, I can make you my Pizza Noodle Soup, LH!" Mikey said gleefully and hugged his friend, which made Leatherhead smile.

"That sounds wonderful," Leatherhead said.

"You can have the soup, buddy, I'm more in the mood for angel-food cake," Casey said as he moved his eyes up and down the figure of an unknowing Donatello.

As Raph and Leo watched Casey ogle their brother they could only ask themselves one thing in their minds: how would Splinter break Casey's bones?

Splinter had indeed seen Casey's eyes wandering over the body of his son. Clearing his throat, he said, "Before we all retire for the night, I have one more question." Pinning Casey to the spot with a harsh glare he asked, "How do you fit into all of this?"

Casey chuckled sheepishly and said, "Well, it's kinda complicated. You see...LH used to be my pet alligator before he mutated."

All four of the turtle's eyes went wide at this shocking revelation. "WHAT?!" they all exclaimed.

"Yeah, surprised me too," Casey said with a grin. "Back then I was just an innocent little 12 year old who loved punk rock; scrawny as hell, and a bit of a chip on my shoulder. Bought an egg from a guy on the street. It hatched into the cutest little gecko of an alligator."

Leatherhead sighed, rolling his eyes at having his past self being compared to a feeble little lizard.

"I thought I was doin' a bang-up job of hiding him. But my parents found out and promptly flushed him down the toilet. You guys know about what happened from there. So anyways, five years later and I'm walking down an alley heading home when this bright flash of light happens, and standing in front of me is this giant two-legged gator! A normal person would'a ran off screaming. Not me, though." Casey smirked as he puffed out his chest a bit, looking every bit the arrogant little punk he was.

"So what? You just hold out your hand for him to shake, like a bonehead?" Raphael asked.

Leatherhead smirked and replied, "More or less," pleased to be able to embarrass Casey in return.

Casey waved it off and continued, "Pfff, whatever. Point is, after I got him calmed down and with a moderately full belly, we got to talking. Traded backstories and found out who we were to each other. Everything else is history."

"Whoa! Like, what are the odds?" Mikey asked, amazed by the whole story.

"Astronomically small," Donatello answered, mind once again at work. "Further proof that chaos theory is a viable explanation to the operation of the universe."

Another blank stare awaited Donnie (with the exception of Casey, who just looked at him with amusement), but before Donnie could explain, Leo interjected with, "Let's leave that mystery unsolved for now. It's getting late and if any of us are going to be useful in this investigation, we should go to bed."

A round of agreement was heard, and so the turtles trudged off to their rooms; Leatherhead and Casey were given the couches to use. Before Leonardo entered his room, Splinter stopped him and said, "Leonardo, while you search for this fossil, and the identity of the client who seeks it, keep a close eye on Casey Jones."

"You noticed it too, Sensei," Leo replied, "how he looked at Donnie."

"Of course I did," Splinter replied, frowning deeply. "And if his intentions are not pure, it could mean grave danger."

Leo bowed and said, "Hai, I will not let him lay a finger upon my brother, Sensei."

"Good," Splinter replied before placing a hand on Leo's shoulder and giving it an affectionate squeeze. "Yoku nemuru (sleep well), my son," Splinter added before walking away.

"Oyasuminasai (goodnight), Sensei," Leo replied before entering his room.