Cori and Donnie followed behind Raph quietly. Cori was constantly checking behind them, making sure they were not being followed. It was hard for her to focus. Being this close to Donatello, she heard every single thought that passed through his mind. They were more chaotic than usual. Not only that, but her arms still ached from his sore wound. She never noticed before how well she could sense other people's pain. Her mother was one of the only people she was mentally linked with, and even then she had never experienced such pain. But, her mother never went exploring in dangerous places either.

The three were slowly making their way down the building. The last few levels all looked the same. Each floor was just a hallway that circled around the building. There was a wall separating them from the center of the room, but nothing more. It was just one big piece of metal. There were no more mutant encounters either, but the three teenagers were still on edge from the last one.

"So, what's with the mask?" Raphael asked while faced away from Cori. She was caught off guard by the question. It was the first thing anyone said since they went to find Leo and Mikey.

"Huh?"

"You know, your whole mask and scarf getup. I mean, we know who you are. You don't have to wear it anymore."

"Why are you wearing a mask, then?" Cori teased.

This time Raph turned his head to look at her. "That's different and you know it."

Cori smirked, making it all the more satisfying knowing he could not see her expression hiding behind the scarf. She paused before explaining, "It's more for my protection, I guess. I don't want to have someone touch my face if it's exposed. The less people I'm linked to the better, you know." Cori tugged on her scarf gently and continued, "And it...makes me feel safe." Raph stole a glance at her and turned back around. Cori had the feeling he felt the same way about this mask.

Another moment passed and Raphael asked, "Why are you so interested in the Kraang? You're lookin' for someone, right?" Cori bit her lip. This was a question she did not want to answer.

"I think I have the right to be curious about aliens invading my city."

"Yeah, yeah. I hate 'em, too. But to run head first into a Kraang base?" He turned around so Cori could see him in the light and held up two fingers. "Two separate times? That's a little more than curious."

"I have my reasons."

"Listen, I'm not saying you can't have secrets or whatever. There's plenty I don't wanna tell you. But, we can't help if you won't let us."

"I never said I wanted your help."

"Hey, you called us here. I'd be fine sitting on my shell back at home and never stepping one foot in this place."

Cori was about to respond but hesitated. He was right, which angered her more than anything. "Well given your track record," she said, "I just assumed you'd show up out of nowhere and ruin everything like always. I figured I should just call you and get it over with."

Raph snorted and said, "Yeah, right. Without us, you'd be mutant dinner right about now. Right Donnie?"

Donnie did not respond.

Cori turned to look at the turtle. Sweat beaded on his forehead, slowly dripping down his face. His eyes drooped, and he was panting heavily. Cori had a hard time reading his mind. His normally organized thoughts were now erratic and almost incohesive. Raph stopped to look at his brother. "Don?" He asked while shining his light on Donatello. He looked ghastly in the harsh bright light. He took a moment and stared at Raph.

"What?" He finally said out loud.

"You don't look so good, Donnie."

"I'm...fine…"

Donatello stumbled forward; his legs shaking. He tried to take another step but could not lift his feet. He started to fall when Raphael caught him.

"What's wrong with him," Raph asked with concern.

"I think—I think I…" Donnie started to say, but he could not finish. Cori gazed into his eyes and finished his thought for him. "He thinks he's been poisoned by that snake mutant."

"Poisoned? What are we supposed to do?"

Cori continued to peer into Donnie's mind. His thoughts were too muddled and confusing. He was struggling to even stay awake. "I—I don't know," she finally said.

"Well, we need an antidote, right? That'll fix him."

"Where would we even get an antidote though? I doubt you have one just lying around for snake mutant venom."

"Then let's get him out of here. Maybe there's something that can help him back at the lair."

Donnie started to shake his head. "We need…" he started saying in a soft voice.

"What? What Donnie?" Raph asked his brother. His brow furrowed as his brother tried to talk again. He could not get the words to come out, no matter how hard he tried.

"Donatello," Cori said in a calm tone. The turtle looked up at her as she took off her glove again. She placed her hand on his forehead; his skin was hot and clammy. The puncture wounds on his arms burned much more than before. She could read his mind a little better now, but it was like searching through a thick fog. "What do we need?" she asked the turtle.

Donnie closed his eyes and slowed his heavy breathing. It was easier for him to think when Cori touched him. Cori watched Donnie for a moment before finally saying, "We need to find the mutant."

"What? Why? That was the thing that made Donnie this way."

"Exactly. We need its venom to make an antidote. He might be fine without it, but I don't think we should take the chance."

"It could be anywhere in this building! How are we going to find it?"

Cori took her hand off of Donnie's face and went to his side. She picked up his other arm and draped it across the back of her neck. She placed her hand on his plastron, restoring her link with him. He seemed better when they were connected. While Cori could not stop the poison from taking its effect, she could still take his pain away. "I don't know," she finally responded. "We should find the others. They could help us find it. Have you tried calling the guys again?"

"Right."

Raph let go of Donnie and pulled out his t-phone. He dialed Leo's number saying, "Please pick up. Please pick up." It rang a couple of times. There was no response. He dialed Mikey this time. No response. Raphael growled and started to pace. "They never answer when it's actually an emergency. They better have a good excuse when I see them. Like they got eaten! Or they're fighting a horde of mutants!"

Cori sighed and said, "If we can't get them to help, we'll just have to look ourselves. I mean, how far could it have gotten?"

"Yeah, it's only what? A forty story building?"

"Better than fifty stories."

Raph's shoulders tensed as if he was going to respond, but he never did. He silently turned his back to Cori and walked away. Cori rolled her eyes but said nothing as well. She helped Donnie forward, following Raphael close behind.

The already dark hallway was illuminated only by Raph's flashlight, as Cori could not use hers while supporting Donatello. Cori tried her best not to trip on anything but would occasionally stumble from some rubble or one of Donnie's missteps. "Slow down, Raph," she whispered loudly. He did not say anything, but she noticed his footsteps became slower. Despite his tough demeanor, she could tell how worried he was about his brother. He was more tense than usual. Yet his anger seemed like an exaggeration, hiding his true concerns from the others. Cori grumbled to herself as they descended another flight of steps. Trying to keep Donnie from tumbling forward was the biggest challenge.

They reached the bottom and looked around. Just like the last level, it was just one large hallway circling around the center of the room. They continued walking silently. Cori was about to ask Raph to stop when he paused. He squinted while looking ahead. "What is it?" she asked. Raphael ignored her and flickered his flashlight on and off. Cori was confused at first until she saw what he was looking at. There was a faint red light illuminating from ahead.

"C'mon," Raph said in a low tone. They cautiously approached, taking even slower footsteps than before. On the previous floors, the center circular wall was completely blocked off. Here, it was clear that the red light was emanating through an open door. Raphael and Cori shared a look before stepping through the doorway. Inside was a very tall chamber that stretched for a couple stories. Embedded in the metal hall was what looked like cages. They were hexagonal in shape, some being very large and some being very small. The cages were stacked on top of each other up to the ceiling. Some cages had a glowing red force field, but it was very few. Most of the cages were battered and broken. There were several glass platforms in the middle of the room, connected to a pillar stemming from the ceiling. The pillar sharpened to a point after the last platform.

In the center of the room, a large black creature hunched over something. Cori and Raph stood very still while watching it. There was a sickening wet sound as it pulled something apart. At its feet was a long winding body. While she could not see most of it behind the giant creature, Cori could see its perfect human face. "Well, we found the snake," Raph whispered. "Hopefully, we didn't need it alive." The dark creature reached down again and pulled at the snake mutant's body with its mouth. It ripped its muscles apart before chomping down on them.

"Holy chalupa!" Donnie suddenly yelled. He stared at the mutant with his mouth agape. Raph and Cori whipped their heads around and shushed him.

The creature gulped and sniffed the air. Slowly, it turned its head towards the others. It was hard to see any distinguishable features with its thick black fur. But, Cori could see its large glistening eyes and its bat-like snout. Blood dripped around from its muzzle as it watched the three teenagers. It straightened its back, becoming much larger than before. It was probably twice Raph's height, if not more. "I really hate this place," Raph said while pulling out his sai.

The two locked gazes, waiting for the other to strike first.