Author's Note: I came up with this origin story to go with a Turtles AU that would combine elements of the various Turtles movies, comics, and cartoon series. I don't see getting to that story for a while, but this stands alone, so I decided to post it as-is.

Splinter's Tale

A Teenage Mutant Ninja Turtles Fan Fiction
By Chronos the Cat

Splinter, April, and the four Turtles sat in a circle in the Den of the Turtles' Lair. After a moment of silence, Splinter began to speak.

"Our tale begins hundreds of years ago, in feudal Japan. Just as Europe had it's "middle ages", so too, Japan had an age of warring states. Instead of Lords, Kings, and Popes, it had Damios, Shogun, and Emperors. And instead of knights, it had Samurai.

There were also another important group of people in feudal Japan, one not present in feudal Europe. In modern, western terminology, they would be called "spies" or "assassins", but to the Japanese, they were "onmitsu", "shinobi", or "ninja"...

There were once hundreds of different styles of ninjitsu, and, as with most occupations during feudal times, these teachings were often passed down from father to son. As a result, these oniwabanshu, or groups of onmitsu, became known as "ninja clans".

Among the most feared and respected of the ninja clans was one known as "the Foot". So great was its prestige that unlike hundreds of other clans, they did not die out when Japan finally achieved peace during the Mejii Restoration. Instead, they became one of a select few ninja clans that continued working for the government in secret."

Michaelangelo interrupted. "You know, like the Men in Black?"

The other Turtles groaned, and Donatello slapped him in the shoulder.

Raphael growled out, "No such thing!"

Leonardo scowled at Raphael and Michaelangelo. "Quiet, you guys!"

Raphael grunted, while Michaelangelo said, "Sorry."

"We now move forward several hundred years, to the nineteen-sixties. It was during that time that a young man by the name of Hamato Yoshi was quickly rising in the ranks of the Foot Clan. Yoshi had a rival, however, a man by the name of Oroku Nagi. They competed in all things, but nothing so fiercely as for the love of a woman – Tang Shen.

Shen's love was only for Yoshi, and when this became apparent to Nagi, he flew into a rage, and attacked her.

When Yoshi went to visit Shen, he found her beaten and violated.

Even among Ninja, such acts are not allowed. Yoshi could have, indeed, should have, contacted the Council of Eight that ruled the Clan. Nagi would doubtlessly have been punished for these actions, and steps would have been taken to ensure it did not happen again. However, in his anger, Yoshi could not bear to think of handing this over to someone else. He felt the need to punish Nagi, personally.

He gathered his weapons, tracked Nagi down, and challenged him to a duel to the death. This was against the rules of the Clan – killing a fellow Foot was forbidden, and would result in expulsion from the clan, not to mention criminal prosecution. However, neither man was thinking rationally at that point, and Nagi accepted the challenge.

In the end, Nagi lay dead at Yoshi's feet. Tang Shen's honor had been restored – but at the price of Yoshi's own. He fled the scene of the crime, and returned to Shen's side. He explained to her what he had done, and that the only way he could regain his honor would be to commit sepukko – ritual suicide.

Shen would not hear of this. To have these deeds done to her, then to loose her true love as well? Instead, begged him to flee the country with her. They would start a new life somewhere else, where the Foot and the Japanese police couldn't touch them.

...And so, before the night was out, and the investigation of Nagi's murder had truly begun, Yoshi and Shen were on a plane to America.

They settled in New York City, where they found an apartment, and Yoshi, a job. They married, and lived happily together, although to their disappointment, Shen could not bear child due to her injuries. Instead, they cared for what pets the land lord would allow – fish, reptiles, and rodents, mostly; things you keep in a cage. It was not much of a substitute, but it served.

Our story would end there, with no mutant rats or turtles involved, except that Yoshi and Shen's past eventually came back to haunt them.

...It was a rainy night when it occurred... I remember it well. Yoshi returned home to find his beloved Shen lying on the floor, dead. Above her stood her killer – a man wearing a metal mask, and an outfit covered in blades.

When Yoshi asked the meaning of this, the masked man answered that he was Oroku Saki, come to take revenge for the death of his brother Nagi.

Yoshi was unarmed, but though he had not fought in years, he had not allowed his skill to grow completely rusty. The battle that followed was fierce, and in the struggle, the cages of the couple's animals, four turtles and a rat, were broken. Also, Saki's mask was knocked from his face.

Saki was younger than Yoshi, in better fighting shape, and armed. Thus it was that Saki was able to critically injure Yoshi. As Yoshi lay dying on the floor, his rat attempted to come to his aid, jumping on Saki's face, and clawing at it. Saki pulled the rat from his face, slashed it with his bladed gauntlet, and threw it on top of Yoshi.

Saki could have left then, and Yoshi would have died of his injuries before any help came. Or, he could have finished the man off. Instead, he chose to inflict one last insult upon Yoshi. He took out a canister of glowing green ooze, and flung its' contents onto the couple and their pets. Then he left them to their fates.

...It was a few hours later when I awoke. I discovered to my amazement that I recalled the battle from two points of view – that of Hamato Yoshi, and that of Yoshi's rat, Splinter. Indeed, I remembered both beings' lives equally well. Opening my eyes, I discovered that something incredible had occurred. I still wore Yoshi's clothes, but my body was covered in fur... I had claws and a tail... and feeling my face, I felt the face of a rat. Somehow, Saki's ooze had merged the man Yoshi and the rat Splinter, into a new being.

Certainly, this was not what Saki had intended. My beloved Shen was still dead, and to my horror, the ooze had transformed her corpse, into that of a hideous, deformed, monster. Presumably, this was the fate he had wished upon Yoshi as well. As for the turtles, at this point, the ooze seemed not to have affected them, though it would not be long until I learned differently.

Knowing that in my new form I would never be accepted by human society, and that even if that weren't the case, I would be blamed for Shen's death, I cleaned up the apartment, and left with the turtles, Shen's body, and what belongings I could carry.

After burning Shen's body, as I had no where to bury her, I began looking for a new home. Not only would it be impossible to find an apartment as I was, but even among the homeless, I knew I would be an outcast.

Something in the rat side of me, instinct perhaps, told me to look underground for a new dwelling place, and in time, I found my way into the sewers.

Meanwhile, the turtles had began to show the effects of the ooze – they began to grow ever larger, and their front feet began to develop fingers. Eventually, they even began to walk clumsily upon their hind legs... But nothing could have prepared me for the day that one of them spoke.

Realizing they were as intelligent as any human, or myself, for that matter, I began raising them as my sons. Knowing they would never be accepted by the outside world, I included ninjitsu in their education, that they might hide in the shadows, and fight back if necessary.

Over time they have excelled in their studies, and have each become almost as skilled as I was at the height of my time with the Foot.

And this is the story of my transformation into the man-rat "Splinter", and of the birth of my mutant "Ninja Turtles"."

"That's, 'Teenage Mutant Ninja Turtles," Michaelangelo corrected.

The other Turtles rolled their eyes, and Splinter sighed.