"No!" I shouted, but my words fell on deaf ears. Raphael and Michelangelo were at my side in an instant, while Leonardo and Donatello raced for the closed-door.

"Are you okay, Sensei?" Michelangelo asked worriedly, and my wide eyes seemed to answer for me.

"We'll get her, I promise," Raphael growled. "she will pay."

Leonardo had just thrown open Raphael's door, and stormed in. I heard the frustrated, disbelieving shouts, and still my jaw hung open in shock.

"She got away." Leo hissed, stomping back into the main room.

"Got away? How did-" Raphael shook his head. "My room has no other exits except that one door."

"Please...my sons..." I trailed off, still in shock. What had I been thinking? Kage...My poor Kage. The look she had given me, like I had betrayed her...

"Let's get him on the couch," Raphael instructed, and my boys helped me sit down on the sofa.

"You...you just..."

"Save your life? Yeah, we know," Michelangelo smirked.

"We have to devise a plan," Donatello spoke up. "her trail will run cold if we don't do something. Did she take anything, Sensei?"

"Did she hurt you?" Raphael asked quietly.

"How did she even find this place?" Leonardo asked, perplexed. He shook his head. "Either way, we will find her and make her play for the injustice she forced on you."

"No one hurts our Master Splinter," Donatello said coldly. "someone who tries to attack our family will suffer. I will make sure the intruder pays."

"We should start with the third quadrant of the sewers, that's the area closest to Raph's room." Leonardo spoke up, taking the lead as he always did. "Don and I will scope out Raph's room for any weak points. She might still be hidden in there," Leonardo said, but then shook his head. "probably not, though. Mikey, you and Raph go scope out the sewer. If she's still around, we might be able to catch this intruder."

"You imbeciles!" I shouted angrily, jumping to my feet. "Idiots!"

My sons were quickly taken aback.

"Kage was not trying to harm me! The girl would never inflict pain on me!" I told them harshly. "She was a guiding light when my so called family abandoned me in my own home. How humans act when they are of age Topside...bah. We are not them. We do not follow their ways! Kage was a friend when my family turned traitor! You cannot hunt down a girl who could be called my daughter!"

"D-Daughter?"

"You know her?" Leonardo demanded.

"Kage has been good company for a while now. She is a friend, and a trusted girl. She has kept my secret, your secret, for many years. You know nothing. Any of you." I said hotly. "I raised each of you to be observant, smart. You could not detect a foreign presence in your midst for years! Kage would never harm any of us!"

"B-But she- She flipped-"

"I was teaching her self-defense!" I cried angrily. "I have tried to teach her the same things I once taught you: meditation, tai chi, bits and pieces of martial arts. She is not the enemy!"

"B-But-"

"No buts, you are like little children who think they know everything." I silenced my son. "Kage is a secret. She is in hiding, and wished to keep her existence a secret. She is like us, hiding below the surface. She is like a ninja, but lacks the skills of martial arts. She has watched us for years, from the shadows. Like we did for the world above. You have shattered a young girl's trust. I was supposed to protect her, but you four come rushing in, making assumptions like you know everything! I may never find her again, and all because you thought I was in danger!"

"B-But we saw-"

"Have I taught you four nothing?" I sighed, shaking my head tiredly. "I am a master. I might be old, but I still have a few tricks up my sleeve."

"Sensei..."

"Find my daughter, or I may no longer have sons."