A/N: (Please read, this one's kind of important to the story, not just me being goofy)
Ok before anyone yells at me that Splinter went from rat to human, in the original cartoon series, he WAS Yoshi, living in the sewers as a homeless person and avoiding Saki, with his pet rat, and found the turtles as a human. He changed to rat form because of his contact with the rat. The turtles changed because of their contact with the human, Yoshi. So in the original cartoon, Splinter went from human to rat, not the other way around. Since I happen to prefer that story line, it's the one I followed here.
And, by the way, my medical knowledge is limited to Wiki articles, so please forgive any glaring errors if you see them in the way I describe the medical/science bits of this. The tree I mention is the source of quinine, the medication most commonly used to treat malaria.
Chapter 12 -Run-
"This is fascinating, Katie!" For the first time since his abduction, Donatello forgot his fear and anger. He stared at the screen of the electron microscope, examining a tiny cluster of cells scraped from his own hand. "I've never had a chance to examine the cellular structure at this level of detail before."
"It's closer to the structure of human cells than I would have imagined," said Katie thoughtfully. "The mutation is amazing. You say it was alien technology?"
"Yes. We were exposed to the mutagen as hatchlings," explained Donatello. "We mutated toward human because of our contact with Master Splinter. He changed, too…" he trailed off. He'd nearly revealed his Sensei's nature.
"So Splinter was human, and changed to… what, exactly?" Donatello could feel Katie's eyes on him.
"He changed, that's all," said Donatello shortly.
Katie gave a little sigh of frustration. "Donatello, I understand why you don't trust me, but please believe me, I am not my father. I won't give him any information about your family. You can trust me."
Donatello shook his head. "I'm sorry, Katie, I just can't take that chance. Not with my family's safety at stake. Your father already knows far too much about us. I can't risk giving him any more information."
"I understand," she said stiffly. She turned away and began stacking Petri dishes in the incubator.
"What are you working on?" Donatello asked lightly, trying to change the subject.
"I've discovered a rather unusual anomaly," replied Katie in the same tone. "Here, have a look at this." She took the slide out of the microscope's scanner and replaced it with another. "These cells," she pointed at the screen, "Are a sample of human blood, which has been infected with a rather nasty little virus."
"Malaria!"
"You recognize it?" Katie's eyebrows rose. "I'm impressed."
"I get around," said Donatello. He stared at the screen. "What's this?"
"That, my dear boy, is what I'm working on," said Katie. She stared at the screen as if answers would leap from its depths to her mind. "This compound is a derivative from the bark of a tree we grow here on the island. I believe it's a relative of the chinchona tree."
"Where they get quinine, for treating malaria. I see," said Don, nodding.
"You got it, Ace," Katie smiled, glancing over her shoulder at him. "The difference is, while quinine treats malaria, it can't cure it. This stuff has a more potent effect. If I can figure out how to refine it so that it effects the infected blood cells without causing massive anemia, I may be on the verge of a cure."
"What about transfusions? Massive blood transfusions during treatment, to replace the damaged cells?"
"No can do. Remember, most malaria victims are from rural, poor areas. They don't have the resources for that kind of treatment. Not to mention, I thought of that. It won't work. The chemical is too fast, it destroys the red blood cells too well."
"I see the problem."
"The answer is in the refining process, I know it is. I just have to figure it out," said Katie. She stood up and went back to stacking Petri dishes in the incubator.
"Maybe I can give you a hand."
Katie looked over her shoulder. "You're welcome to take a crack at it," she said with a sigh. "I sure haven't been able to figure it out."
Donatello studied the screen, lost in thought. There was a puzzle here, and he wouldn't give up until he had it solved.
Katie finished stacking the Petri dishes, and turned to watch Donatello. The intent way he stared at the screen, with total focus. It reminded her of her father. She shivered.
"So, what do you do back in your lab at home?" she asked.
"Oh, I'm more into electronics. There aren't a lot of exotic plants in New York," said Donatello, turning with a smile.
"Electronics? You mean, computers and stuff?"
"Yeah. And other things. Anything we needed, I had to design. Communications, transportation, all of it has to be built from stuff we can scavenge. It's kinda hard for one of us to walk into a Radio Shack and pick up a cell phone, you know?"
"I can see the problem," said Katie, smothering a giggle. She sobered. "It's so different from everything I've known. All my life, all I've had to do is ask, and I could have just about anything I wanted."
"Well, it's not exactly your fault you were born into wealth," said Donatello. "You can't pick your family."
"I guess not." Katie turned away. "But I wonder, if I had a chance to trade places with you, would I?"
I know I would, in your place, thought Donatello. He watched Katie fiddle with some empty vials on the counter, absentmindedly straightening them.
"Do you want to go for a walk in the jungle?" asked Katie. "I could, you know, show you around a little."
"I'd love to," said Don. And I can explore this island's defenses, he thought.
"We have a few hours of daylight left. Let's go."
Donatello followed Katie outside. She headed purposefully down one of the stone paths leading away from the house. "Come on, I'll show you my swimming pool,' she called over her shoulder. Donatello shook his head.
Great, another gilded tourist attraction. What I really want to know is, how many guards? How well trained are they? And how do I get this band off my arm?
He hurried after Katie, pausing only a moment at a small stand of sturdy trees. One was particularly straight and solid. That would make a dandy replacement for my bo, thought Donatello. I'd better ask Katie before I harvest it, though. It might be some rare species of tree.
"Come on, Donatello," called Katie. Don hurried to catch up with her. She was standing at a natural archway in the path, her hands on her hips in mock impatience. She tried to frown as he hurried up, but she couldn't hold the expression.
"Come on, I want to show you something," she said, turning aside to let Don pass. He gasped. Before him lay the most beautiful natural lagoon he'd ever laid eyes upon.
The water was crystal-clear, a deep greenish blue. A small waterfall tumbled down over a smooth rocky slide, spilling into the lagoon. White sand completed the picture.
Donatello let out a low whistle. "This is some swimming pool," he said.
"Last one in's a rotten egg!" called Katie. She dashed down the beach, stripping off her top and shorts to reveal a swimsuit underneath. Donatello laughed. He hesitated only an instant before remembering the armband was waterproof. He didn't have clothes to remove, so he hit the water an instant before Katie.
It was deliciously warm in the cooling evening air. Don swam fast, diving deep. The sandy bottom spread out below him. For a moment he thought of swimming across the lagoon, slipping out the other side, and disappearing into the jungle.
It's an island, he thought. Where would I go? And who knows what Kanar would do. Probably hunt me down like an animal. Better stick with Katie for now… At least until I can figure out how to get rid of this band.
He surfaced, blowing out with a laugh. Katie's head bobbed 20 or so feet away. She swam over to him with a strong, sure stroke. "I thought I'd lost you," she said, grinning. "The way you dove like that."
Donatello shook his head. He smiled at Katie, but mentally cursed himself. It probably hadn't been wise to reveal his strength as a swimmer.
"I'm a turtle," he said lightly. "What did you expect?"
Katie laughed with delight. She floated on her back. "I do love it here," she said. She turned her head, glancing at him just above the surface of the water. "I hope you'll learn to like it here, too."
"Well, you sure can't beat the view," replied Don, copying her and floating on his back, his plastron just clearing the water, and gazing up at the deep blue sky showing through the clear space over the lagoon. Katie blushed, but didn't comment. She rolled onto her stomach and dove neatly, cutting through the water toward the waterfall. Don followed, curious. She walked out of the water, and climbed up the rocky path.
"Katie, where are you going?" called Don.
"Watch," she called. Don treaded water, waiting. After a moment, he heard a squeal of laughter, and Katie shot down the waterfall, causing a miniature tsunami as she flew off the smooth stone slide and dropped into the water. Don came up spluttering.
"Want to try?" asked Katie, surfacing a few feet away.
"Watch me," he answered, returning her smile.
Katie moved back, and watched as he made his way up the path. At the top, he leaned over, looking down the steep waterfall, and swallowed hard. He wasn't sure this was a great idea.
But Katie did it. I can't let a human girl show me up! Raph would never let me live it down… Donatello fought down a pang at the thought of the guys. Are they looking for me right now?
"What's taking so long? You scared or something?" Katie's taunting voice floated up from the lagoon. Don smiled grimly, and climbed onto the waterfall. Positioning himself carefully, he leaned back on his shell and let go.
Don had never experienced a water slide before, so the rush of wind and shocking speed were a brand-new thrill. "Waaaaaa-hooo!" he screamed as he plummeted into the pool, dropping like a boulder into the sparkling water. It was Katie's turn to splutter as Don's tidal wave swamped her.
"Hey!" she protested, once she blew the water out of her nose.
Don grinned. "How's that for a cannonball?" he asked.
Katie splashed him. "I should've known that shell of yours would create huge water displacement," she grumbled. "It's a wonder you didn't empty the lagoon."
Don laughed, and splashed her back, scooping the water with his arm to create a flying wall of water. "A shell does have its advantages," he said.
They swam and splashed and slid for another hour, until it began to get dark, before heading back up the path toward Katie's bungalow.
"Hey, Katie, would you mind if I cut this little tree," asked Don as they passed the grove where he'd found the straight sapling. "I'd like to replace my bo staff."
Katie glanced at him over her shoulder, frowning. "What for?" she asked.
"I'm used to carrying it, that's all," said Don quietly.
Katie stopped, turning to face him. She was still frowning. "A bo staff… it's a weapon, isn't it? Like, for karate or something?"
"Or something," said Donatello, wincing.
"I don't know, Donatello," said Katie. Her fingers strayed to the device, and she fingered it unconsciously. "I'm not sure I'm comfortable with you carrying a weapon."
"Katie," said Donatello, standing square and looking her in the eye. "I'm not asking your permission to carry a weapon. I'm asking if it's ok if I harvest this particular tree, out of respect for your research."
"I don't think my father would like it," said Katie. Her green eyes flashed. "I have to keep him happy too, you know. There are no predators, nothing on this island that will attack you. Why do you need a weapon?"
Nothing but your father and his guards…
"Why do you need a laboratory?" asked Donatello quietly, trying to control his temper. "Please try to understand. It's part of who I am."
"I'm sorry, Donatello, I just don't think it's a good idea," said Katie, shaking her head. "My father…"
"Isn't here right now," snapped Don. "Katie, this is between you and I. I'm going to harvest this tree, unless you tell me it's important to your research, and you're not going to stop me." He took a step toward the tree.
Katie's fingers closed convulsively on the tiny black box around her neck. Donatello froze. Neither of them moved for a long moment. Katie's eyes were wide, confused. She stared at Donatello.
No… his mind screamed. Not again. He saw her finger twitch, and in an instant, without further thought, he was running, flying down the path and disappearing into the jungle as only a trained ninja can.