The turtles wandered throughout the abandoned Kraang base. Leonardo led with a flashlight as they avoided various shards of glass and rubble. The brothers arrived mere minutes ago, surprised to find such a familiar sight. Cori had texted the address to Mikey, but none of them recognized the street until they arrived. The building that they were meeting Cori at was the former World Wide Genome Project. It loomed above the rest of the buildings on the street. The building itself was run-down, with many of its long elegant windows broken and smashed. The walls were scorched, leaving behind blackened bricks. It was still relatively intact, although unsightly. It was much different than the first time they were there.

"Look guys, look!" Mikey shouted to his brothers. He ran through a doorway into a large circular room. "Mikey, stick close," Leo shouted after him. His brothers chased after him. It was a tall and very large circular room. A console was set up in the center of the floor, but it was not on.

"Look, it's where Justin was born," Mikey said.

"Can we focus on finding Cori?" Raph asked. "I want to get out of here already. This place gives me the creeps."

"Over here, guys!"

The others turned to find Donnie standing over something; his flashlight illuminated the floor. The rest of the turtles shone their flashlights at it as well. "It's her phone," Donatello said while picking it up. While the screen was shattered, it still worked. The flashlight on it glowed brightly. Donnie turned it off and stuffed it into his belt.

"She was definitely here."

Raph scoffed and said, "Why'd she have to run in without us? If she had just stayed put, we wouldn't be on this goose chase."

"Yeah, like you've never run blindly into a situation before," Mikey teased. He playfully poked Raph, resulting in his older brother grabbing his hand painfully. Mikey yelped and pulled his hand back. He pouted and rubbed it.

"Let's split up guys," Leo ordered. "We need to find her. Mikey, you go with Donnie. Raph, you're with me."

"Oh, so we're still doing this B-team thing?" Donnie asked unamusingly.

"What? No! I just think the two of you are a good pair."

"Why?"

"Er, because you're the brains and Mikey is...Mikey."

"He's got a good point," Michelangelo replied.

"Mikey," Donnie said, "that was an insult." Mikey gasped in an offensive shock.

Leo continued. "I wasn't insulting—you know what? Fine. Mikey's with me and Raph's with you."

"Yes!" Mikey shouted and pumped a fist in the air. He did a little dance and chanted, "I'm gonna be with Leo. I'm gonna be with Leo."

"Me and Mikey will take the elevator shaft down," Leo said to the others. "We'll head to the bottom and work our way up. You guys start up here and go down. Hopefully, one of us will run into Cori, and then we can get out of here."

Raph crossed his arms and watched as Leo and Mikey left the room. He looked over to Donnie and asked, "So, how does it feel being on the A-team?"

"Wouldn't Leo be A-team?"

"What? No way. I'm what makes us A-team."

"Well, with him being the leader and all, I figured he's what makes it A-team."

"I don't know where you got that idea, but you're all wrong."

The two turtles left the room and continued down the hallway. They eventually came upon a set of dimly glowing stairs. They continued down a flight and explored the floor below. "I can't believe we're doing this," Raphael grumbled.

"Oh, would you quit it already?"

"What?"

"I'm tired of you complaining about Cori all the time."

"It's not my fault she decided to go around exploring a creepy old Kraang base."

"Yeah, cuz you've never run off on your own, and then we have to rescue you."

"Hey, that was only one time!"

Donnie gave him a skeptical look. "Okay, maybe it happened more than once," Raph admitted.

The two finished exploring the floor and went down another flight of stairs. "All I'm saying," Raphael continued, "is that I think we have enough going on. We don't need some girl to come in and give us someone else to look after."

"You didn't seem to have a problem when you met Casey."

"That's not true. We fought when we first met."

"Yeah, and then you became friends like ten minutes later."

"I can't help it. He's very charismatic."

Donnie scoffed at Raph's comment. They continued going down and exploring each flight. Some of the floors were too smashed and destroyed for them to safely explore. Each floor was nearly identical to the last. The only difference being that sometimes a door would lead to an inner chamber room. But, it was always abandoned with nothing nor anyone there.

After walking a few minutes in silence, Raphael whispered to his brother, "Hey Don, can't you like...talk to her with your head or something? Like with your brain?" Donnie's shoulders dropped and his head rolled back in frustration. He sighed loudly and responded, "Why does everyone think I can do that? I don't know exactly how Cori's powers work, but it doesn't go both ways. She can feel what I feel and hear my thoughts, not the other way around."

"Figures."

Raphael was about to ask another question when he heard a snort from behind. He spun around and jerked his flashlight up. "What? What is it?" his brother asked.

"I don't know. I thought I heard something…"

The two heard clacking footsteps and quickly drew their weapons.

"Who's there," Raph called out into the darkness. He only received another snort for a reply. A large animal walked into the light, as tall as Raphael himself. Its head hung lower to the ground, it's back rising above. It stomped on four cloven hooves. Large horns decorated its head, with two large curled ones on each side and a long horn protruding from its snout. It turned its head to the side and looked at the turtles with its strange eyes. Its pupils were horizontal, almost rectangular. The creature was completely covered in thick brown fur.

"Donnie," Raph whispered nervously, "what the shell is that?"

"I don't know. It must be some type of mutant. I've never seen an animal like that. It almost looks like a rhino."

"Great. It's looking at me weird."

The mutant snorted louder this time and turned its head straight forward. "What's it doing," Raph asked his brother. The creature tilted its head down and grunted. "I think it's time to run," Donnie said. The creature kicked one of its feet off the ground and charged forward.

"Right now!" Donnie screamed as he ran away. Raph was close to follow.

The mutant stomped after them as the turtles ran in fear. They continued running until they heard a loud crash. The animal let out an ear-piercing whine. Raphael stopped and turned around. He flashed his light to find a large hole in the ground behind him. The creature laid at the bottom, wriggling out of the newly made rubble.

"That's it! I'm done! We're grabbing the others and leaving."

Donnie ignored his brother and started to think out loud. "Interesting. These must be those hybrid animal mutants the Kraang were making when we were here last. They must have broken out and roamed the building ever since it was abandoned. That thing must have been some sort of rhino-goat mutant."

"That's great, Don. You think there's more of them?"

"Oh, I'm not sure. Probably. I'm sure the Kraang made more than one. There must be some sort of containment area in this place where they used to be kept."

"So, what now? We explore a creepy monster infested Kraang lair until we find Cori? I mean, how do we know she didn't get eaten by one of those?"

"Actually, neither rhinos nor goats are carnivorous. They're both herbivores so it's very unlikely she was eaten. Although, that's completely ignoring the possibility that there aren't any more mutants here that are carnivorous." Raphael glared at his brother. Donnie paused before adding, "She's probably okay."

"Let's just grab Cori and get the shell out of here."

Raphael jumped through one of the holes in the ground to the lower floor. He looked back to the pile of rubble where the rhino-goat was. It stood next to the pile but did not notice the turtle further down the hall. It panted heavily, blood leaking out from its side. "C'mon," Raphael whispered to his brother. He waved his arm and motioned for him to come down. Donatello followed, landing softly on his feet. He looked at the mutant with curious wonder but was dragged off by his brother.

The two turtles continued their exploration, much more carefully. They sneaked around in silence; their footsteps untraceable. As they continued, all the floors resembled each other exactly. Just a long hallway circling around a smooth metal wall. There were no doors to get into the interior room. Just one long hallway after the next. Raphael and Donatello walked down another flight of stairs. While not exhausted, their limbs grew heavy and their breaths shortened. The constant stress of encountering another mutant made their hearts beat fast and wildly.

"Geez, how big is this place?" Raph asked.

"Well," Donnie said between breaths, "there's probably about thirty to thirty five floors judging by the building's height. We've gone down about twelve now. We should be meeting back with the others soon. But, I'm guessing they haven't found Cori yet, otherwise they'd call us. Unless their t-phones broke or were lost. Or Cori got eaten, and they don't know how to break the news. Or that they all got eaten—"

"Donnie."

"Sorry. I'm just a little freaked out right now."

"Yeah, you said it. This place gives me the creeps."

"Maybe we should call the others? Just in case, I mean."

"Good idea."

Donnie was about to pull out his phone when they heard footsteps ahead. Raph immediately pulled out his sai and yelled, "Who's there?"

"Way to be stealthy, Raph," Donnie snidely commented.

He raised his flashlight and illuminated the curved hallway. The footsteps grew louder and louder. They were very fast. Donnie cautiously reached for his bo staff. He gripped it without sliding it off his back. The two brothers shared an unwary look with each other but still maintained their defensive stances. Around the bend emerged Cori. Her mask and red scarf completely covered her face, but her hood was down. Her dark brown hair fluttering behind her. She ran right between the two turtles, not even stopping to talk. They jumped out of the way to avoid her. "Hey, watch it!" Raph grumped. Donatello shined his light on Cori and watched her run away.

"Uh, Raph…"

"Yeah?"

Donnie slowly turned back to the end of the hallway that Cori entered from. "What's Cori running from," he asked sheepishly. His hand trembled, shaking the flashlight ever so slightly. Suddenly, a large creature crawled into sight. It wriggled its body and dragged its large tail against the floor. It crawled by hauling itself with two large human-like arms. Its face was almost human as well. There was something off about how emotionless its face was; it was almost like a mask.

Raph and Donnie screamed and sprinted back the way they came. They quickly caught up with Cori, who stumbled a bit more while running than they did. The two turtles started to pass her. Raph grabbed her arm and practically dragged her along. Donatello hastily looked back to the monstrosity chasing them.

It was quick. Much quicker than them. It would soon catch up.

Donnie suddenly tripped on a large piece of rubble and fell over. He landed hard on the ground, scratching his knees on the floor. His flashlight flew out of his hands and landed elsewhere on the ground. He grunted in pain and rolled himself onto his back. Raph was still running when he noticed that Donnie had fallen. "Don!" he yelled after his brother. He stopped sharply, nearly knocking Cori over.

Donatello's flashlight shined towards the monster. The mutant hissed, but not with its human mouth. A large mouth unfolded from underneath its chin. Its snake-like tongue flitted while it shrieked. It was almost upon the fallen turtle. It lunged towards him with a gaping mouth filled with sharp razor teeth. Donnie swiftly pulled his staff out and held it between his two hands. The hybrid mutant bit into the staff, causing it to splinter. Saliva pooled out of its mouth and onto Donnie's skin. The turtle whimpered as it bit down harder. The wood twisted until it finally snapped. Wood splinters flew as his weapon broke.

The mutant reeled back its head and lunged again. Donnie instinctively covered his face with his arms. He cried out in pain as the monster's fangs dug deep into his forearms.

"Get away from my brother, you freak!"

Raph jumped and kicked the mutant. It released its grip on Donnie and faltered to the side. It turned its attention to Raphael and screeched again. Raph yelled back and went to stab at it with his sai. The mutant weaved back and forth, avoiding his attacks.

"Stay still, would ya?" he shouted in frustration.

The snake mutant whipped its long tail at Raph's legs. He fell onto the floor as his feet were swept from underneath him. With its hands, the monster pinned Raph to the ground. Raphael could smell its putrid breath. He turned away and gagged. Before the monster could bite him, it reeled upwards in pain. Raph looked over to see Cori, standing next to Donnie with her arm out. She had thrown her knife at the monster. The creature backed off of the turtle and clawed at the knife. It was lodged into its side. With his newly freed arms, Raph skewered the mutant in its neck with his sai. It screamed loudly, forcing the teenagers to cover their ears. It slithered away, whimpering. Raphael watched as it slowly disappeared into the darkness. It left behind a trail of dark blood. He continued to lay on the ground, catching his breath. Cori crouched next to Donnie, helping him as he struggled to sit up. Blood flowed from the numerous bite marks on his arms. While it could have been worse, Cori could still feel the pain that Donnie was in.

"You...okay?" she asked, panting heavily. She had not caught her breath yet from the chase. None of them had. "Do I look okay?" Donnie complained. He cradled his arms over his lap. Raphael finally stood up and walked over to Cori and his brother.

"If I see one more stinking mutant in this place…" he started to say, never finishing his threat. He kneeled down next to Donnie and looked at his arms. "I have some bandages," Donnie offered, "in my left belt pocket." Raph reached over and opened the pouch. He pulled out a roll of gauze and started to unwind it. "Hey Cori," Donnie started to say. "Next time you see the Kraang, wait for us."

"Or better yet, don't tell us," Raph added.

"I'm sorry," Cori said quietly. Raphael was surprised she had no snappy comeback. Even though her face was completely covered, the brothers could tell how remorseful she was.

"It's okay. You didn't know about the freaky mutants. Right, Raph?" Donnie looked at Raph expectantly.

"Uh, yeah."

Raph reached over and grabbed one of Donnie's arms. He winced and hissed through his teeth.

"Ow! Be gentle."

"Quit whining."

Raph firmly gripped his wrist and started to wipe off the blood with a spare piece of gauze. Donatello cringed and closed his eyes tightly. While Raph continued, he saw some movement in the corner of his eye. Cori had taken off one of her gloves and reached over to place a hand on Donnie's shoulder. She grunted as her warm hand touched his skin. Her arms felt like they were pricked by many large needles. She could feel each bite mark on her own skin. The pain slowly intensified, starting to burn. She curled her other hand into a fist. Donnie's face slowly relaxed. His painful expression was replaced with a confused one.

"What...how'd you do that?"

"What?" Raph asked, not seeing what had happened.

"I don't feel anything."

"Huh?"

"I mean, I don't feel any pain anymore. It's gone!"

Donatello's eyes glistened with excitement. Raphael looked up at Cori. Her shoulders tensed and her hand trembled a bit. He watched as her chest raised and fell methodically. He could hear her heavy breaths over Donnie's babbling. "Is this because of our mental link? All along, I thought you could only hear my thoughts. But to share someone's pain...that's incredible! I have so many questions. How long can you do it for? Indefinitely? Can you only do it while touching my skin? Do you always feel my pain? I wonder if—"

"Donnie," Cori interrupted through gritted teeth, "if you keep asking questions, you're gonna feel a lot more pain than before."

"Sorry…"

Raphael smirked at Cori's comment while he finished wrapping Donatello's arms. "Alright, you're all fixed up now," he said while wiping some dried blood off his hands. Donnie's forearms were covered in tight white wrappings. Specks of red started to spread in the fabric. "I feel great! I've never felt better." Donnie flexed his arms. Cori slowly released her grip on his shoulder. The pain rushed back to Donnie. He immediately dropped his arms and winced. "Nevermind."

"Where's Mikey and Leo," Cori asked abruptly.

"Somewhere else in this nightmare of a place," Raph answered. "Let's call 'em and get the shell out of here already."

"We can't leave yet. We haven't found the Kraang."

"If the Kraang are even still here. They probably already left by now."

"Or got eaten," Donnie added.

Cori stood up and said, "I'm not leaving until we find out what the Kraang were doing here."

"Are you insane?" Raph stared at her incredulously. He stood up as well, leaving Donatello sitting on the floor. "Donnie was almost dinner for that thing we just fought. I'm not sticking around to see what other freaks live here."

"You can leave. I'm staying."

"You're crazy!" He looked down at his brother and gestured at Cori. "She's crazy!"

Donnie slowly stood up and said, "Let's at least call the guys to make sure they're okay first. Alright?" Cori crossed her arms but did not disagree. Donatello pulled out his T-phone and called Leonardo. There was no answer. He called Mikey. No answer. "Well, that's just great," Raphael complained. He started to pace a bit as Donnie formulated a plan. "I guess we'll keep moving. We're bound to run into them."

"Or that snake monster. Or another mutant," Raph grumpily added.

"I'd rather search the place rather than stay here," Cori said. "I don't want to be sitting here like fresh meat for a mutant."

"Fine," Raph groaned, "but you're sticking close to us. If you get lost again, we're not going to find you."

"I didn't get lost," Cori said defensively.

"Yeah, I'm sure you knew where you were going."

"I was doing just fine before you came here."

"You were being chased by a giant snake monster!"

"Well, if you guys had actually come when I called you, I wouldn't have gone in by myself."

"We live on the other side of the city! How were we supposed to—"

"Guys!" Donnie interrupted. "Maybe we should quit the yelling? Need I remind you that this place is filled with hungry mutants that want to either kill or eat us?" Raphael snorted and turned his back to them. "Whatever, just stick together." He grabbed his flashlight and shined it down the hall. He started to walk away without the others.

Donnie rolled his eyes and leaned down to grab the flashlight he dropped. "Here," Cori said as she grabbed it for him. "I'll hold it," she said. Donatello groaned but did not refuse. His arms hurt enough without the strain of carrying something. They followed after Raph, walking deeper into the Kraang base.