Author's Note: Welcome, ladies and gentlemen, to my self imposed crossover month. I noticed this section doesn't spazz out at the sight of crossovers, and had just the right age set for this universe to coincide with others. And thus, enter the Invader Zim crossover. Future chapters will be longer – this is just sort of an intro. Bare with me; I'm not good at long intro sequences.

I do not own Invader Zim or Fillmore.

------------------------------------------------------------------

There came a time in everyone's life where they were forced to wonder if they were cut out for their job.

For Fillmore and Ingrid, murder was that moment. For the entire Safety Patrol, the unasked question of 'why are we handling this' floated through the air. The tension, particularly on Vallejo's end, was thicker than it had ever been before. Danny immediately grabbed a rule book and said that the youngest kids on the Safety Patrol didn't have to investigate violent crimes. General chaos reigned within the office for an hour.

In that chaos, the Patrol's two star officers were mentally debating whether or not they could handle this. On the one hand, they were the best on the force when it came to initial investigations. That would be key in bringing this person down. On the other hand, this was out of their league. Experience or not, neither one had any experience with murderers. This was out of the Patrol's hands at this point. They didn't have the profiling techniques, the man power to keep up their normal work and investigation, or the faintest idea where to start. But even in their own heads, it was a fruitless argument. Fillmore and Ingrid could never let someone kill a student and walk away from it.

The building had been evacuated onto the opposite side of the campus, excluding those who had been in the room when it all went down. They were held as suspects currently, albeit in another room. Officers, both of the Safety Patrol and police force, walked the halls of the building and lurked in shadows, watching. No one would be able to so much as go to the bathroom without a full body search at this point. Tehama went to work alongside the forensics officer as Anza stood nearby, ready to interrogate people one on one if he had to. Ingrid set up her laptop, pressed the appropriate button so that it would record, and nodded to Fillmore.

Strolling to the front of the line of students, with a cursory glance at the body, he cleared his throat and started to speak. The assembled students stood warily in a straight line, like a police line up. Except that this time, singling someone out would be a lot harder than just asking someone to step forward.

Fillmore stared out at them, grimly. "Your rights have been read to you. You've been told you will be detained until further notice. What you haven't been told is why. To put it simply, we're here to find out who killed Dib." His eyes settled on one particular girl with purple hair, who smirked defiantly at him. "And we're not leaving until we do."