Mike stood in the control center of his Mindscape, screens surrounding him and a desk full of various buttons and a keyboard in front of him. A few of the screens showed programming code scrolling by while the majority showed various hallways and doors, representing the various parts of his mind. Mike himself was typing furiously at a keyboard, doing everything he could to slow down William's takeover. So far the invasion was mostly isolated to the cyber part of his mind, though creeping magenta lines of energy slowly starting to appear on the walls of the hallways and creeping along the floors showed that his true mind wasn't completely unaffected.

"Why do you keep up this pointless struggle," William's voice taunted, coming from everywhere and nowhere. "You know you're only delaying the inevitable. So why don't you save us both the time and trouble and just let me in."

Mike ignored his father's attempts to distract him and just focused on cutting off as much of William's access while he could. While the firewalls Ford installed kept some of Mike's core programming hidden and safe, such as the safety measures they had installed, William was slowly bypassing the other security blocks and taking over more and more of Mike's functions. If Mike's body was conscious right now, he knew he wouldn't have any control of his animatronic limbs and very little chance of regaining control of them.

Suddenly his Mindscape shuddered slightly and William's presence became chaotic and distracted, a shout of pain echoing for a moment. Mike wasn't entirely sure what happened, but Mike immediately took advantage of it, using the chance to regain back some of his mind. Unfortunately, William recovered fairly quickly and began taking over the areas Mike had just reclaimed.

"Whatever you did out there Dipper," Mike murmured, firmly believing his brother must have caused whatever had just happened. "I hope you and the others are safe."

Mike couldn't afford to spare any more thoughts on the others as he went back to slowing down William as much as he could.

"This is the entrance," Vanessa said, nodding towards the rickety elevator hidden under Rozy's Raceway. "I'd recommend going down no more than two at a time… it's not exactly the most sturdy thing… But I refuse to go down there again!"

"This is the way to his lair alright," Dipper agreed with a grimace. Even just standing at the top entrance as they were, he could feel the dark and malicious energy leaking from deep below. It was already enough to make the protective charms react, glowing softly as they kept the animatronics from being affected. Turning to Vanessa, Dipper said, "We're not to force you to come with us. Not only would that be cruel after all you've been through, but it's also a terrible idea. You're still vulnerable since you've only been recently freed and the last thing we want is for you to get possessed again. Chica will go with you to wait at the entrance for us. She'll be able to message the other Glamrocks if you need help."

The unspoken addition was that Chica would be able to keep an eye on Vanessa as well.

Vanessa nodded in agreement giving one last shudder as turned away from the elevator, following Chica out of the area. Once they were gone, Dipper turned to the others, the animatronics specifically, and said, "This is your guys' last chance to back out as well. The protection charms will only be enough to keep you from being possessed, but that's about it. You'll be vulnerable to anything else William will throw at us, supernatural or otherwise. It's going to be dangerous and I won't be able to focus on protecting you. So only come with me if you're willing to take the risk."

"You already know I'm not going anywhere," Gregory replied with a smirk, Helpy giving a thumbs up from his place in Gregory's arms.

"And I promised to keep Gregory safe," Freddy added, placing his hand on Gregory's shoulder.

"Like you'd be able to without me! I'm the best after all!"

"He was using my strength to attack and destroy… I want to be able to use it to protect you and Gregory now."

"Evil men must be punished!"

Dipper smiled in relief at the conviction that the others were showing, knowing he'd probably need all the help he could get. With them all in agreement, they began going down the elevator in pairs. Monty and Moon go first, followed by Roxy and Freddy, with the two humans going last. They came into a rocky tunnel and signs of the crumbling foundation of the Pizzaplex. A generator was nearby and when Dipper turned it on, a few lights that had been jury-rigged to the walls came to life.

The group followed the lights slowly down the tunnel, turning on the generators as they came across them. The evil presence in the air got thicker with every step, the protection charms growing brighter in response. Gregory subconsciously stepped closer to Dipper as they walked, unknowingly seeking Dipper's much more friendly magical aura to protect him. Dipper in response placed a comforting hand on Gregory's shoulder, though he never stopped scanning the area for threats.

The tunnel eventually opened into a larger area, but most of the space was taken up with the surprisingly mostly intact remains of an old building, the somehow still mostly functioning sign lit up to display the name "Freddy Fazbear's Pizza Place".

"Of course," Dipper said with a grimace, looking up at the sign. "I should have realized that this would be the lair. We knew the Pizzaplex was built on its location after all…"

"You know this place?" Gregory asked looking up at the sign himself.

"Yeah, this was the restaurant Mike ran for about a week about a decade ago," Dipper explained. "It was designed to lure and trap the remaining killer and possessed robots that had been roaming around at the time, including the one William was haunting. Mike burned it to the ground along with everything inside in an attempt to purge that evil once and for all."

"It doesn't look very burned," Gregory replied with a grimace. Sure he could see ash and burnt marks on the outer walls, but nothing like the kind of destruction Dipper was hinting at.

"I'd seen the aftermath of the fire and believe me this place was barely holding together," Dipper insisted. "The fact that it's been restored this much is just a sign of how strong William's presence is. Once we enter, he'll have the advantage as ghosts have complete control of their lairs. Don't trust anything we see."

Suddenly there was a shift in the atmosphere around them as if something else and others had entered the area. This new presence seemed to flood the area around them with pure anger, making the humans falter for a moment at the intensity of it. The only relief to Dipper and Gregory was that the anger didn't seem directed at them. The animatronics lacked the ability to sense the emotional auras pressing down on them, but they did notice the way Dipper and Gregory tensed and started scanning their surroundings even more intensely.

"What's wrong superstar?" Freddy asked, looking around for whatever it was that had the humans on edge.

"It's hard to make anything out with all the junk and stone," Roxy said as she looked around with her special eyes. "But I think I see something… There!"

Gregory pointed his flashlight in the direction that Roxy was indicating. Even with the extra light, it was hard to make anything out in the gloom, but it looked like something was slithering back there…

CRASH

The sudden loudness made the entire group jump in surprise and it wasn't hard to find the source of the noise. There was a large withering mass of black wires and cables with what looked like various Fazbear character masks scattered throughout it currently attacking the old building. Its larger tendrils hit the was with a lot of force, enough to make huge cracks appear, but the building seemed to heal itself faster than the blob could destroy it.

"What is that thing?" Gregory gasped in fear at seeing the strange and violent thing before them, hugging Helpy closer to himself. "Is it one of those possessed animatronics you were talking about?"

"There's definitely ghostly influences behind it," Dipper said, pressing the buttons on the side of his glasses to switch to a setting that would let him see the supernatural energies at work. "But it looks like it's being puppeted by a ghost rather than directly possessed by one. Let me just… Revelare spiritum!"

Dipper's eyes and hand glowed as the spell took hold, forcing the ghost controlling the blob to reveal itself. Before them was the ghost of a young girl, wearing a yellow shirt and blue overalls, faded to nearly grey in death. Black stains covered most of her chest and neck area, no doubt from the wounds that had killed her. Her black hair was tied in pigtails, floating ethereally and flickering as if they were made of flames. Dark streaks were carved into her cheeks as if her tears had been so abundant that they permanently scarred her skin. Her eyes were black voids with only tint pinpricks of white light, but they burned brightly fury all the same. A snarl was on her face as focused all her attention on her assault.

"Hey!" Dipper called with a wave of his hand in an attempt to get the ghost girl's attention. "Do you happen to be Cassidy?"

The reaction was immediate, the girl shuddering as her name was said and her burning gaze snapping towards them. Between one blink and the next the girl went from floating near the blob to right in front of Dipper, looming close to his face as she demanded, "Who are you!? How do you know that name!?"

"My name is Mason Pines," Dipper calmly explained, unflinching at the very angry spirit before her. The animatronics tensed at the potential threat, but Dipper signaled for them to stand down as he continued. "And I know your name because I have learned about a lot of the Fazbear Tragedies, especially those surrounding the Aftons. I know you were one of the victims of William's…"

"Don't speak his name!" Cassidy snarled, her hair becoming even wilder for a moment in her anger. "He doesn't deserve to have his name remembered for what he's done! If you know what he did then you know why he must be destroyed! He must be made to SUFFER!"

"Trust me I want him gone just as much as you do," Dipper said firmly, getting a scoff from Cassidy. "But my brother's in there and I can't let you destroy this place until we've rescued him!"

"Your brother!" Cassidy laughed, a cruel mocking sound. "I've watched everyone who has ever entered and left that place so I KNOW who's in there… and you claim him as a BROTHER? If you truly know about the Afton then you must know what HE'S done and what he does to BROTHERS! Trust me DIPPER… it's better if he burns along with his father. They both DESERVE it!"

"That's not what Evan thinks," Dipper replied, causing Cassidy's laughter to cut off instantly. "He's already forgiven Mike for what's happened, so you don't need to seek revenge on his behalf."

"Evan was always TOO forgiving for his own good," Cassidy replied with a frustrated huff. "Always claiming that Michael was "different" and that he "changed"… As if MURDERS would ever CHANGE!"

"But that is not for you to decide," Dipper replied coolly. "Evan and Mike have made their peace over their history with each other and if you try and take revenge in Evan's place, you're disrespecting his wishes. So out of respect for Evan, I ask you to hold off your attack until we rescue Mike."

"…Fine…" Cassidy reluctantly agreed before a wide grin split her face. "But I'm not going to just sit here and wait. I can't enter HIS lair on my own, but you can help me inside…"

"Are you sure that's necessary?" Dipper swallowed nervously, knowing exactly what Cassidy was referring to.

"That's the DEAL," Cassidy said, holding out her hand which seemed to glow slightly brighter. "Either you help me get inside or I go back to trying to pummel this place to the ground! No matter whose inside!"

"Fine," Dipper agreed with a glare, his own eyes and hand glowing as well. "I'll allow you to connect to me only to get you inside until you can exist there under your own power and will, then the line must be broken."

As soon as they shook hands, their energy intertwined and a glowing string of light seemed to connect their hearts before fading from view.

"Pleasure doing business with you," Cassidy purred, beginning to fade from view. "I'll be watching and waiting for the perfect time to strike…"

"What was that about?" Gregory questioned as soon as the ghost girl disappeared. "What did she do to you? Is it dangerous?"

"She's using my soul as an anchor," Dipper replied, subconsciously rubbing the spot where the tether was. "The dead can go to places the living can't and vice versa. By temporarily tying my soul to hers she can have a way to bypass the barrier William no doubt has set up to keep her out. It's not inherently dangerous… Especially as the deal is specific enough that she can't really do anything to me. I just don't like making deals…"

"Well, we're wasting time waiting around here!" Roxy declared pointing to the building. "We've got our favorite cyborg to save after all! Let's go get him!"

The other's rallied around, Roxy's declaration, and together they opened the doors and stepped into William's lair.