Donnie ran across the crates towards the Walker. "Here goes nothing," he mumbled to himself as he slid to a stop and threw a circular, explosive device the size of his palm at the Kraang weapon. The Walker detected the movement of the device and kicked in its defenses, shooting the explosive before it made it halfway. Donnie covered his face as the device was prematurely detonated. He then stared in disappointment at the non-damaged Walker, and noticed the Newtralizer running across the crates behind it. He leapt up and landed on the antennae on top of the Walker, damaging it and putting its defenses offline. The Kraang in the Walker now had no way to shoot the alien off the roof. A chain reaction began to take effect from the damage. The roof of the Walker shook as several pieces flew out, followed by smoke. Newtralizer walked to stand above the glass dome that held the Kraang beneath it. The Kraang saw his cockpit grow dark in shadow, and slowly turned to look upward as the Newtralizer smashed through the glass. He grabbed the small, pink alien and tossed him away, taking control of the Walker with his feet. He aimed the blaster at the Kraang droids on the ground, and they scattered to avoid the discharges.
"Kraang Walker has been Kraang-jacked by the alien amphibian," one of the Kraang announced. "Kraang, retreat. Retreat." They began to flee the area as Newtralizer laughed. He followed the retreating Kraang in the newly obtained weapon, carelessly shooting off blasts in every direction. Slash was still taking out Kraang droids individually with his mace, and found himself in the path of the Walker. Newtralizer didn't see him, or didn't care enough to change course. The Walker's large foot was raised in the air mid-step above Slash's head. He looked up in time to see it start coming down on him, having no time to react.
"Spike!" Raph shouted, charging at his former friend to push him out of harm's way. Their landing wasn't very graceful, but they weren't squashed, and that was what was important. Raph sat up, holding his head.
"You," Slash began after sitting up as well, shaking his head to clear it. "You saved me, Raphael." Raph didn't have time to respond as both of their attention was grabbed by the Walker. A blast was being aimed at them, and they had to move quickly to get out of the way.
The Newtralizer continued to laugh at all the destruction he was causing, "I'll destroy you all!" Slash was not pleased with his partner's behavior, and teleported on top of the Walker to confront him.
"What are you doing? They helped us fight the Kraang," Slash told Newtralizer angrily.
"This is my battle. I don't need them," Newtralizer growled back. Slash frowned, narrowing his eyes. He charged forward and slammed his spiked mace into the surface of the Walker right next to where Newtralizer was seated. The metal twisted and was torn up, trapping Newtralizer. He squirmed, trying to get free. "Slash, how could you, brother?" he growled.
"You're no brother of mine," Slash told him flatly. Newtralizer growled, furious that Slash had betrayed him. He raised his wrist blaster towards his former partner and prepared to fire. The yellow glow lit up in the barrel and was seconds before discharge, but it was thwarted when a ninja shuriken struck into it. The crackle of electricity sparked lightly around Newtralizer's wrist, and he turned to see Raph with a second shuriken in hand, smiling smugly. He jumped down to stand next to Slash. Newtralizer paused a moment before turning forward to the Walker controls. He pulled a lever forward, moving the Walker in the same direction and causing Slash and Raph to lose balance.
"Raaaph!" Mikey cried as he saw his brother and Slash fall to the ground. Donnie and Kris ran by his side. Kris shifted into a cheetah and sped ahead of the turtles, getting underneath Raph long before he was near the ground. Kris paused in cheetah form for a short moment, thinking about what he should do, and then quickly became a giraffe. He stretched his head out towards Raph, who gently grabbed his neck and slid down it to decrease the speed of his fall. Slash crashed to the ground, his large shell protecting him from most of the impact. Raph let go of Kris's neck and fell on top of Mikey, who had attempted to catch his brother. "Caught you, bro." Mikey said, slightly dazed, while Kris returned to his human form.
"Raka raka raka!" Newtralizer growled from on top of the Walker as he aimed its blaster at Slash, Kris and the other turtles. "Raka raka roka raka!"
"Goongala!" called a familiar cry as the goup in danger looked up. Casey, who had followed his friends to the docks and waited for the right moment to prove himself to them, stood on one of the crates across from the Walker with a lineup of explosive pucks. He struck them with his hockey stick and they flew towards Newtralizer, detonating on impact. The explosions were small, non-lethal, but effective in distracting the Newtralizer.
"Casey? You're back?" Raph asked, looking up at his friend.
"I figured I'd wait for you all to be in trouble, and then I'd make an awesome heroic entrance," he replied, posing heroically. "Pretty cool, right?" Kris rolled his eyes, smiling at Casey's typical reasoning, while he and the turtles turned back to the Walker with Newtralizer inside. They all grinned with new confidence. They charged at the weapon, attacking as one. They went for its legs, knowing that was the key to toppling it. Raph threw his sai into the gears near its ankles, while Leo and Don attacked closer to the Walker's knee joints. Kris hovered in the air and held onto one end of Mikey's nun chuck chains as the turtle leapt around the tall legs of the Walker, wrapping it up in his chains as he did. He and Kris pulled on the chains once Mikey was back on the ground and the Walker lurched forward. It rocked back and forth before Newtralizer regained control and broke the chain by walking forward to separate the legs. Kris flew back when the chain snapped and was knocked into one of the crates. The turtles cried out and retreated back against another set of crates, cornered with no way out. They jumped back as several blasts struck the ground in front of them, but they were running out of room to retreat to. Casey was running along the top of the crate, avoiding blasts from Newtralizer as well. He jumped to avoid one, and tumbled onto his stomach. He looked up at the Newtralizer, racking his brain for a way to stop him. What they needed to do was take out the Walker, or just get Newtralizer away from its control. Then Casey's eyes lit up, noticing a small port in the Walker's side. It was just big enough for one of his exploding pucks to fit through, but that left no room for error. Casey would have to hit a perfect bullseye. He held up his puck with its fuse lit, eyes determined and focused on the target. He dropped it onto his stick and flipped it through the air a few times, catching it again. He tossed it gently into the air and drew back his arm, swinging it forward again with force. He struck the puck in midair and it flew towards the port. Casey hit his target. The puck dropped through the port and into a small compartment inside the Walker. There was an alien crystal in the center, surrounded by a ring of pink/purple energy. No mistake, that this was the energy source of the Walker. The Newtralizer continued to laugh, oblivious to the scheme Casey had put into action. The explosion sounded, causing the alien newt to look around for its source. By detonating inside the Walker's energy source, Casey had started a chain reaction. More explosions rang out, stronger and louder than the exploding puck. The top portion of the Walker jumped up, and crashed back into the lower portion. It began to wobble on its tall legs as Newtralizer lost control of the malfunctioning weapon. He tried to flee, but remembered that he was stuck. He pushed against the Walker's surface, unable to free himself from the twisted metal encasing his legs. He moved to plan B, and attempted to activate his teleporter. But it had been damaged along with his blaster when Raph had thrown his shuriken.
Kris was finally starting to recover as he sat up and saw the Walker was now swaying quite violently. Newtralizer started hitting his teleporter in hopes he could get it to work. He faded in and out as the teleporter tried to comply with his command, until he finally disappeared.
"Yeah!" Casey shouted, pumping his fist into the air when he saw the Newtralizer flee. Casey, Kris and the turtles shielded their faces as the Walker exploded into a pink cloud that rained down on them.
"Awe, yeah! You've been newtralized, son!" Mikey cheered. He, Leo, Donnie, Kris and Casey high fived each other, as Slash and Raph walked off behind them to talk alone. "Thanks, Spike. I mean, Slash," Raph began. "You know, there's always room on the team for one more."
"I need to go my own way, raphael. Think I'm better off solo," Slash replied. Raph's smile dropped in disappointment, and his eyes turned to the ground. "Good bye, brother," Slash continued, before turning to Casey and the other turtles. "I'll see you all again. Someday." He activated his teleporter and vanished.
"Good bye … Spike," Raph spoke solemnly to the space where Slash had been. He turned away in sadness, deeply missing his former pet and best friend.
"Don't sweat it, Raph," Casey told him, placing his hand on the mutant's shoulder and spinning around him so his arm wrapped around in a side hug. "You still got Casey Jones on your team."
"You did awesome, Casey," Raph told him, bringing his smile back. "Best partner a turtle could have."
"It's been a long day, guys. Let's go home," Leo suggested. He began to walk home, and his brothers and friends followed.