A/N: Thanks to all the reviewers and those who've added this story to their "favs" list. I'm really floored at the number of reviews, and the enthusiasm you've shown. Thanks so much!
The real trouble starts in this chap.

Donnie: Heh she thought she could flip me.

Mikell: Aww, Don, you're such a softie. See, starring in fan-fics isn't so bad, after all.

Donnie: *blushing* Well...
On with the story!

Mikell: Hey, that's my line.

Chapter 24 -Normal-

"Donatello, look at this," Katie was gazing at the electron microscope's screen. "The chemical, it's attacking the blood cells, again. The new process didn't fix the problem."

Don leaned closer, watching. The red blood cells on the slide were exploding into swirling puffs of color, their cell walls breaking and releasing their fluid to dissipate into oblivion.

"What if you added a coagulant?" he asked, thinking aloud.

"Nuh-uh. Doctor Serling said it would cause clots and not stop the cells exploding," responded Katie.

Donatello tensed at the mention of the woman's name. Katie glanced up at him, and sighed.

"I don't know, Donatello. It's just so frustrating. I feel like I'm so close, and yet the answer escapes me." She leaned back in the chair, rubbing a hand over the back of her neck. Donatello hesitated, then put his hands on her shoulders. Katie flinched, glancing up at him in confusion. He smiled, and rubbed her shoulders gently.

"Ohhh," she moaned, letting her head fall forward. "Where'd you learn to do that?"

"My friend, April. She gets stiff shoulders from sitting at the computer."

"There's a girl turtle?" Katie's head snapped up. She leaned back, resting her head against his plastron, to see his face. Donatello blushed.

"No," he said quietly. "April's a human friend."

"Hmm. I don't know if I like that, Donatello," said Katie with mock severity. "I might get jealous."

Donatello snorted. "Oh yeah, and what are you going to do about it?" he asked innocently.

"This!" Katie caught his wrist, pulling him forward and off balance. Donatello recovered quickly before she could pull him to the ground, spinning her around.

"Hey," Katie yelped as he caught her wrists and pinned them to the arms of the chair. She squirmed, but Donatello wouldn't relent. "No fair, using my own computer chair against me!"

Donatello laughed, releasing Katie's hands. "That's what you get for trying to pull a fast one on a ninja," he scolded.

"You're the one who said to use the element of surprise," Katie grumbled, but her green eyes were sparkling with laughter.

"Well, if you're in such a playful mood, maybe we should go out and train for a while," suggested Don. "Goodness knows you could use the practice…"

He grunted as Katie's fist caught him in the plastron, though she couldn't punch hard enough yet to cause him any real discomfort.

"Oh, darn it." She shook her hand. "I forget about that shell…"

"One of the advantages of being a turtle," remarked Don smugly.

Katie swung around and caught him neatly in the stomach with a kick. She knocked him back a step, but she hadn't put any real intention behind it, so the force was minimal. Donatello caught her ankle neatly, and swept her other leg out from under her. Katie landed with a thump on her backside.

"Yep," said Donatello sagely. "You definitely need the practice."

"Oh, you!" Katie grumbled, getting to her feet. She rubbed her smarting rear. "I'll get you for that!" Donatello laughed easily.

"What is going on here?" The sharp voice made them both turn. "I come to visit my daughter, and find you knocking her about?" Donatello fell to the ground as Damien Kanar hit the button that activated the device still attached to Don's arm. His and Katie's combined skills had not yet found a way to remove it.

"Stop it! Father, stop!" He heard Katie screaming, as if from far away. The pain stopped in an instant. Sweat dripped down his forehead, stinging his eyes, but Donatello forced himself to roll to his knees. A sudden wave of nausea made him retch. He swallowed the bile that rose in his throat, and struggled to his feet. Katie caught his arm.

"Katie, I… he was hurting you." Damien Kanar grabbed Katie's arm, pulling her back, away from Donatello. Don managed to stand, and faced the man squarely.

"Father, we were playing. Donatello's been teaching me to defend myself. Why did you do that?" Katie stared at her father, shaking and pale.

"He was attacking you," said Damien Kanar stubbornly, glaring at Donatello. "Katie, you have that button for a reason. You can't be too soft to use it!"

"Father, there is no reason for me to use it! Donatello is my friend. If you really cared about me, you'd take that horrid band off him and let him go." Tears slid down Katie's cheeks.

"Do you want him to leave, Katie?" Kanar looked at his daughter, his black eyebrows rising. "I knew it! He was hurting you, wasn't he? You don't have to be afraid to tell me, Katie, I'll take him away…" His finger hovered dangerously over the button as he glared at Donatello.

"No! No, Father, I don't want Donatello to leave, but I…" she glanced at Donatello. "I want him to be happy."

"He should be happy, Katie. He has everything here, everything he could ever want. What more do you want, Turtle?" Damien Kanar turned to Donatello. "Tell me, what luxury could we provide that would keep you happy here with my daughter?"

"There isn't anything your money can buy, Sir," said Donatello calmly.

Damien Kanar snorted. "You see, Katie? He's just ungrateful, like all the rest. Let me take him away now. I'll find you another companion. One who appreciates the benefits of living here."

"No, Father," said Katie sadly. "Please. I don't want another companion. I want Donatello."

Damien Kanar regarded his daughter for a long moment. He shook his head, and sighed. "Katie, you know all I've ever wanted is to make you happy. He held out his arms, and Katie reluctantly came into his hug, giving him a quick squeeze before backing up.

"Father, please… take the band off him. Please."

"No, Katie. It's a matter of safety." Kanar frowned, glancing at Donatello. Don could read suspicion in his gaze.

He thinks I'm influencing her… this might not be good, he thought.

"Katie, it's all right," said Donatello quietly.

"It's not fair!" Katie stamped her foot. She crossed her arms and glared at her father. "Why can't I just be normal? Why can't I have normal friends who aren't dragged away from their homes and families? Why can't you trust him, Father? He saved my life. He's not going to hurt me."

"Katie…" Damien Kanar frowned. "Leave us," he said to Donatello. "I must speak with my daughter privately."

Donatello nodded. "I'll see you later, Katie," he said mildly. He left the house and walked toward the lagoon, thankful for the chance to get away from Kanar.

Glad that's over. I guess it's a good thing I wasn't carrying my new bo when he came in. Who knows what he would've done. Maybe training Katie isn't such a great idea after all…

Donatello wandered down the path toward the lagoon. The water sparkled, inviting, but Donatello didn't feel like swimming. He made his way around toward the rocks, determined to climb the waterfall and see if he could see past the canopy from the top.

"Katie! Katie, wait!" He heard Kanar shouting, and ducked into the undergrowth, not anxious to meet the man again. "Katie! Come back!"

Damien Kanar's voice was coming from near the bungalow. Don slid further back into the leaves, and slipped to edge of the rocky embankment leading to the waterfall.

He climbed to the top and leaned over Katie's natural water-slide, peering toward the path. He couldn't quite see the bungalow from his perch, but he spotted movement in the leaves, leading away from Katie's little house. Damien was still calling.

She must've argued with him, thought Don. He sat down, his shell resting against a large rock. I'll just stay up here, out of the way, until things settle down.