April's apartment was still a mess, but it was getting to be less of a mess than it had been. The Turtles were using all their ninja skills to clean it up.

Donatello cleaned with a mop as well as he fought with his bo. Leonardo had dusters on the tips of his katana swords. He could even dust the chandelier that way. Raphael speared litter with his sai.

"Hey, guys, check this out!" Michelangelo said. He had a can of furniture polish in one hand, a cloth in the other. He sprayed April's table and began polishing. "Wax on. Wax off."

Raphael tossed a soggy sponge at him.

"Mouth off," he said. It worked.

The door opened and April walked in. She couldn't help but notice the Turtles' efforts - including a five-foot-high stack of empty pizza boxes.

"Thanks, guys," she said, smiling. "Say, where's Splinter?"

"He's been up on the roof of the building ever since he saw your report. I don't know what he's doing up there-"

"Coming to a decision." Splinter spoke from the windowsill, where he was standing.

Leonardo bowed to him. "You've been meditating many hours, Master Splinter."

"Yes. And it is time. Join me above," Splinter said.

Without question, the Turtles followed him up the fire escape. April came, too.

"These last hours have been spent pondering many questions," Splinter began. "Some are the very questions of our origin: the sewer. Our transformation."

Raphael was curious about what Splinter was going to say, but he couldn't help thinking that Splinter could be almost as tedious as April's Professor Jordan Perry. He kept this thought to himself.

"But the answers have always remained hidden in the past, veiled by a shadow too deep to penetrate. Until now."

Raphael and his brothers were curious.

"A light from the present reaches back to illuminate that shadow." Splinter reached into his cloak and removed an old canister, broken into two pieces.

"You have never seen this, but know what it is."

"That's the canister that had the ooze-" Leonardo began excitedly.

"That transformed us all," Splinter finished for him. "I have kept it all these fifteen years."

"But why do you show it to us only now, Master Splinter?" Leonardo asked.

Splinter held the two pieces, one in each hand. Slowly he rotated them, fitting them back together as a whole. That was when the Turtles and April could read the label that had been split when the canister broke.

"TGRI!" April said excitedly. "I knew it! I knew there was something else going on with those guys!"

"Yes," Splinter agreed. "And we must know exactly what it is. For if the contents of this canister are not unique, the city may now face grave danger."

The significance began to sink in. The Turtles had always enjoyed the things that made them different from the rest of the world. Even though they were clearly mutants and different from everybody else, they'd been able to use their differences for good purposes. They had no trouble living with their present. It was their past that was hard for them. They were always eager for some kind of hint or explanation about their origin.

Donatello thought of these things as he looked at the canister in Splinter's hand. "Not knowing who we are - how we are-"

"The past returns, my sons," Splinter said. "It is time to seek our answers."