Author's Note: Although this is a TMNT story, it's a bit of a cross-over with Sonic the Hedgehog. Mostly TMNT, though. I love both series, and I thought it would be neat to try to make a cross-over of the two. Sonic fans are welcome to scream and run at this point.

:p

Reviews are appreciated so much. Thank you for reading!


A brisk night hung over New York City, and the paved streets lay fairly quiet. Afew people wandered around here and there, but the city was more peaceful than usual. Given it still had as much traffic as nighttime usually had, it was realitively quiet. Or at least, it was quiet by New York standards. Yet all those men in suits, and gang members wandering the dark alley ways, and teenagers hanging out in groups on the street corners... None of them thought to look up at the silver moon, or at the clear sky, or at the very least, up to the roofs of the buildings. If they had, they would have spotted the foursome of brothers laughing and playing, leaping from roof top to roof top.

"Step it up, guys!" Leo laughed, looking back over his shoulder as he ran. "If you keep going that slow, you won't make it home until Tuesday!"

"Cram it, Leo," Raph panted, pushing himself to run harder, trying to keep up. Just behind him, Don and Mikey slowed to a jog.

"I'm getting tired of this game," Mikey declared. "Too much running. Let's play Ninja Stealth."

"I agree with Mikey," Don admitted. "Let's save the running for later. Master Splinter said we could be out as late as we liked, provided that we would be ready to train when he gets up. So I'm all for Ninja Stealth."

"Whatever. It could give me a good chance to kick big mouth Leo's shell." Raph smirked, slowing down, too. "Yo Leo! We're switching over to Ninja Stealth. Wanna play?"

"Ah, why not?" Leonardo smiled, and promptly jogged back. "So who's it?"

"Rock Paper Scissors," Michelangelo suggested easily. "Fairest way, if you ask me! Besides, when we do Spin the Sai, Raph cheats."

"I do not!"

"Sure you do!"

"Guys, cut it out," Don interjected calmly. "Rock Paper Scissors it is. Leo, you go against Raph, and I'll go against Mikey. Winners have to face off, and whoever loses is 'it'. Got it?"

The other three nodded.

Raph beat Leo's scissors with a rock, and Don beat Mikey's rock with paper. After insisting on a replay because "paper doesn't beat rock!", Don won again by defeating Mikey's feeble paper with scissors. And so, Don and Raph faced off for their decision of who would be "it".

"Don't use paper, Raph," Mikey urged. "Donny finds ways to make it work against you!"

Raphael didn't listen, but he didn't need suggestions anyhow. He beat Don the same way he'd beat Leo.

"Alright," Raph said. "We'll hide, and you count to a hundred. No cheating, though! Those night vision goggles of yours gave you the advantage last time."

"Fair is fair," Donatello agreed. "But you guys can't leave this block, or I'll never find you!" He sighed, and pressed a hand over his eyes, slowly beginning his count. "One... two... three... four..."

"No peeking, Donny!" Mikey called, and Don heard his footsteps rush off into the distance and dissapear. He'd probably leapt to the next building top. He heard Raph and Leo run off in opposite directions, too. He'd find Raph first. He always tried to hide somewhere "unobvious", but his "unobviousness" was becoming predictable. After a minute or two of counting, he neared the end of his count.

"...Ninety seven... Ninety eight... Ninety nine... One hundred!" His eyes flew open. "Ready or not, here I come!" he shouted. He pulled his bo staff out from its place on his back and snuck carefully to the next roof. Ninja Stealth wasn't much different than Hide-And-Seek. The only real difference was that whoever was "it" had to sneak up on the whoever they were tagging. Don was careful, though. He made his way to the edge of the roof, and peeked over the side. Huh. So Raph wasn't hiding on the ledge this time after all. There was a fire escape ladder that led part of the way down off the roof. He snuck over to it, peering down. One of Mikey's nunchucks had gotten stuck on one of the rungs of the metal ladder. He couldn't be too far away...

He crept down the ladder just far enough to retrieve the nunchuck. Michelangelo would be looking for it as soon as he discovered it was missing. "He needs to be more careful sometimes," Don thought, tucking it into his belt for safe keeping. He peeked around the corner of the building. Nothing. Apparently his brothers had thought of better hiding spots since last time. Maybe Raph had gone down into an alley. Alleys were dark and often secluded, and that seemed like just the sort of place he'd like to hide in. Don decided it would be best to check around them next. He jumped down from the end of the fire escape ladder, landing in a crouching position on the sidewalk below. He rose to his feet, scanning his surroundings. No one was around to see him.

Sneaking into the alley way at his left, he glanced around. It was darker there because the light of the street lamps didn't reach in far enough, but he could make out the outlines of trash cans and the like. He heard someone exhale. Hah! One of his brothers had to be down here, and he was pretty sure his guess about Raphael had been right. Now Raph would have to help him find Mikey and Leo. Smirking at his success, he moved forward carefully. He didn't want Raph to notice him. He tightened his grip on the bo staff and reached it forward to jab his brother. Nothing.

Well aware of the fact that he was not alone, he tried again to hit Raph with the bo. Again, nothing. He repeated this process until he had become frustrated. "Alright, that's enough, Raph," he sighed frustratedly. "I know you're here. I got you, okay? Now help me find Leo and Mikey." No reply. Donatello rolled his eyes. He hated it when Raph decided to play dirty. He pressed his hand to the wall next to him and felt along it. He could distinguish a door. This was probably where the people took out their garbage, so there had to be a light somewhere. He fumbled overhead for a dangling string and gave it a tug. Light poured into the area around him.

"Raph," he started, "stop being so--"

A pair of bright blue eyes stared at him, shocked, afraid and unblinking. Donatello, in turn, stared as well.

What was it..? Orange and fuzzy, the little creature stood probably just over two feet tall. No wonder his bo staff had missed it. It looked like a fox; the sort of fox you'd see in a cartoon. White gloves covered its hands, and it wore red and white sneakers. Two tails moved vaguely from side to side behind it. Its right hand clutched the upper part of its left arm, and it stared at Don with a curious mix of awe and fear.

Not unused to strange beings from other worlds, or even aliens for that matter, Don wasn't frightened, but he certainly was a little confused. And suspicious. Where did this thing come from? And what was it doing here? It was no triceriton, or Battle Nexus ally. It looked misplaced and surprised, and moreover... wounded.

"I... uhm... " Don began, hoping that it understood English, and hoping further that it might respond in said language. But it didn't. It stared at Don another few seconds, took two steps away from him and abruptly collapsed. Don's bo staff clattered to the pavement next to him.


On the other side of the building, Raphael rolled his shoulders and yawned. Donny sure was taking his time. He didn't know exactly what time it was, but it was late, and he could tell because the air was getting chillier. If Don didn't find him in the next five minutes, he'd go find him. They needed to get home soon. Footsteps sounded, nearing his hiding place under a window ledge. He perked up, wondering if Donatello had finally managed to locate him after all.

Michelangelo appeared around the side of the building, panting a little. Leo was at his heel. Both looked surprised to see him.

"Donny's not with you?" Mikey asked worriedly between pants.

"No..." Raph responded slowly. "He didn't find either of you?"

Leo shook his head. "He didn't. We thought maybe he found you first, and you guys were looking for us. I guess not..."

Raph jumped down from his place and joined his two brothers. "I wonder where he went? Don's level headed. He's usually good at finding us. Maybe we should just go back to the lair, and he'll meet up with us once he realises we left."

"Master Splinter wouldn't like it," Leo insisted sharply. "We have to go back together."

"How the shell are we supposed to find him?" the red bandana wearing turtle queried. "We got a whole city block to check out, and we're gettin' a little short on time."

"There are three of us now, though," Leonardo replied. "We split up. I'll take the roof tops, Mikey can take the sidewalk, and you can go between buildings. Sound good?"

The other two agreed.

In total, they spent about fifteen minutes scouring the block, looking for Donny. Leo took to the roof tops, as he'd said, and found nothing. Mikey went around the whole block, careful not to be spotted by any random passerbys, and also found nothing. Needless to say, Raph found just as much as his brothers did. Nothing. Concerned, the three met up on the corner of the roof of an apartment building.

"I guess there's nothing more we can do," Leo said. "We'll just have to head back to the lair. Donny will figure out we've left and probably come back. I hope he's okay."

"And I hope Master Splinter isn't still awake when we get home, or he'll see us without Donny. And then we'll get in trouble for not sticking together." Michelangelo sighed. "Oh well. I guess we'd better take our chances. C'mon!" He leapt down from the small apartment building with a cry of "Cowabunga!"

"Bonehead," mumbled Raph as he and Leo followed.


When the trio of turtles arrived back at the lair, they were soundly surprised. All of the lights were on. Did this mean Master Splinter was still up? Were they doomed? Mikey poked his head into the doorway, peeking around to check for their rat master. He couldn't see him. Motioning for his brothers to follow, he snuck noiselessly into the well luminated room.

"Guys!"

All three of them jumped.

Donatello appeared in their bedroom doorway. "I wondered when you'd realise I was gone," he said playfully in a hushed voice, barely audible from where he was.

"Donny!" Leo hissed. "You scared the shell out of us! Why did you leave like that! We thought Master Splinter was going to kill us for losing you, or something!"

"I can explain," promised the purple bandana wearing turtle. "Come on. I'll show you. But be quiet." He wandered over to where the sofa sat facing their many TV screens. Stopping at the side of the sofa, he waited for the others to follow. They exchanged a glance before cautiously creeping over to where Donatello stood.

"Alright," he said seriously. "Promise me you won't make a big fuss. I'll explain to Master Splinter when he gets up." With a green two-fingered hand, he gestured to the sofa. Mikey approached it first, looking over the back.

"Uhm... do you think it's safe harbouring weird alien things in our house?" he asked.

Leo and Raph both took a look, too. A small fox lay face up with its eyes closed. A blanket covered it, pulled up right to its chest. The three turtles gave Don a skeptical look. "I know we've dealt with inter-dimensional beings before, but I think this is kind of risky," Leo told him honestly. "Do you even know what dimension this thing came from? I mean, how do we know it won't try to attack us?"

"Trust me," Don said firmly. "It doesn't look like the type. It was terrified of me, and it blacked out. It's hurt, too. I couldn't just leave it. It had to have come here by accident, and if the people of New York saw it, they' all just freak out. I mean, they're not exactly accepting of anything alien to their planet, especially after that triceriton invasion."

"You'd better hope Master Splinter doesn't kill you, Donny," Raph cautioned. "And since you found it, you have to tell him. We ain't doin' it."

"I know, I know." Don crossed his arms. "I'll take the blame."

"Take the blame for what, my son?" Just behind him, Master Splinter was exiting his bedroom, walking stick in hand.

"Don found a weird thing and so he brought it back to the lair!" Mikey blurted before anyone else had a chance to say anything.

The old rat raised a bushy eyebrow. "Is this true, Donatello?"

"Yes," mumbled Donny sheepishly. "It's probably from another dimension, and New York isn't a safe place for it if it's not from around here. Besides, it was hurt. I had to do something. I'm sorry..."

"It is alright." Leaning on his walking stick, Splinter made his way over to where the turtles were standing. He carefully noted their visitor, either still unconscious or asleep. "Hmm," he said thoughtfully. "Very well. It may stay until we have found the means to return it to wherever it came from."

"Yes, Master Splinter." Don bowed respectfully.

"Now, go and get some sleep," he instructed. "But be ready for training in the morning."


Tails yawned and thoughtfully recounted the strange dream he'd had during the night. Something about bright light, and soreness, and big green monsters... It was sort of all mushed together in his head now. He stared groggily at the ceiling for what felt like several minutes before realising it was not his own. It was a sandy-colored stone ceiling. He blinked at it, clearing his vision. The stone ceiling didn't go away, nor did it start to look anything like the ceiling of his own bedroom. He felt color drain from his face. This didn't look familiar at all. He didn't even recall coming here.

Sitting up slowly, a pain in his arm caught him by surprise. The upper half of his left arm was secured well with bandages. A vague splotch of blood had made itself partly visable through the layers. What? Didn't he dream that? His mind pounded with his frantic thoughts as he tried desperately to latch onto something, anything, familiar in this place. His eyes darted to the side. Many TVs in varying sizes stared blankly at him, their screens dark. He became aware of sound behind him. Soft sounds, like light footwork.

Dreading what he might see, Tails slowly turned his head to peer over what was apparently the back of the sofa he was on. A green monster with two swords was hopping swiftly around lit candles with its eyes closed. With blinding speed, it put out every second candle with only the weapons. Nearby, a grey rat observed its technique.

The little fox began to feel light headed from shock and confusion. That green monster he saw in his dream was real? Had that even been a dream at all? Overwhelmed, he flopped back down onto the pillow, gazing hopelessly at the ceiling. No explainations surfaced in his mind. He couldn't explain any of these things; how they got there, where they came from, why he was having anything to do with them.

Unfortunately, the rat had noticed him. It rose to its feet.

"Leonardo," it said quietly. "We will resume your training at another time. I think it best that we summon Donatello..."

The green monster paused, turning to look at the rat. "Why, Master?"

"Because our guest is awake."