The Protectors au.
Willow had been indulging in an off the books research investigation. Her curiosity about the perception filter or somebody else's problem field, which ever term worked best, around Sunnydale was a puzzle that demanded to be solved. She knew Giles probably wouldn't approve of her methods so she simply didn't tell him. She figured she'd present any evidence of her findings and as they say 'ask forgiveness, rather than permission'.
After hacking several systems and downloading blueprints and files, she carefully reviewed everything. What she had found so far was...kinda scary. She had downloaded blueprints for every structure in town, from the first one built, to the most recent. She'd discovered two things. One, the tunnel system under the city was planned and built first, in its entirety and carefully maintained. Not that big a surprise when you consider the need to run pipes and for run off, except these tunnels mostly weren't used for those things. Oh some of them were, but most had no pipes running through them or run off running into them. They simply was no logical reason for eighty percent of the tunnels under the city of Sunnydale. Or the multitude of access doors, some of which were actually built in tombs. Until you remembered the vampires.
The next thing Willow discovered was that every building company that worked in Sunnydale was required to buy the cement used for the foundations of any structure or building from one company and one company only. Didn't matter what the structure was, all had to buy the cement, especially for the foundation, from this one company. The cement this company sold was also used in creating and maintaining the tunnels under Sunnydale.
Curious, Willow pulled everything she could find about the company. It was one of the oldest businesses in Sunnydale. It was owned by the Wilkins family, as in the Mayor Wilkins, father and grandfather, like himself, who had been the mayors of Sunnydale since its founding.
She decided to go further and pulled everything she could on the recipe this company used to make the cement it sold. There were ingredients she didn't recognize in their recipe that weren't found in any other company's recipes for cement. Willow began checking these extra ingredients out. All of them, including Lethe's Bramble, were magical ingredients. And all of them were used in spells for mind control and memory suppression and erasure. Spread out around the town was a magically created forget-me field.
Faith had been patrolling with Xander and Cordelia tonight. It had been mostly uneventful. Uneventful until they were attacked by a large force of more than twenty vampires, that is. Cordelia immediately called in reinforcements via walky and Tor and Heidi, and Kyle and Rhonda raced to help, while Faith and Xander gave her cover from the vamps. The three of them were holding their own when the others arrived, they had just finished off the last one when a human seemingly randomly wondered into the battle. Turns out, it wasn't so random. He introduced himself as Deputy Mayor Arthur Finch and had information about the Mayor. Xander grabbed his own walky and said. "All call. Repeat. All call. Assemble. Library."
The Pack and Faith met Jesse, Willow, Giles and Jenny in the library. Deputy Mayor Finch began to tell them his incredible tale. Mayor Wilkins was over one hundred years old. Actually, he was closer to one hundred fifty years old. He was also the only Mayor Sunnydale had ever had. He'd been pretending to be his own father and grandfather. He'd traded his soul for longevity. But that wasn't his end goal. Oh no, he had bigger plans than that. Mayor Wilkins wanted to be one of the Old Ones. As in a dinosaur size demon. The Protectors, who's memories included Protectors fighting and dieing and ultimately defeating the Old Ones, shuddered when they heard that.
Willow, meanwhile, filled them in on the results of her extracurricular research activities. Giles carefully reviewed her findings and agreed with her conclusions.
Giles contacted the Council with their findings and their information about the Mayor. They were definitely shocked. They agreed to provide a safe haven for the deputy mayor and dispatched a team to pick him up. As to the magically created forget-me field, short of destroying the town, there wasn't much that could be done about that.