FBI Headquarters

3:45 p.m.

"The suspect's name is Olivia Rodriguez," read Agent Scully from the case file given to her that afternoon. "She is wanted for two counts of homicide. In both cases, the victim was strangled with her prints found on the throat, but, and here's the good part Mulder, Olivia's arms were amputated from the wrists down four years before."

If there had been a window in the basement office, Mulder would have been staring out of it. Instead, he had to settle for the concrete wall. Scully looked up and straight at Mulder.

"You okay?" she asked, genuinely concerned.

"Yeah," Mulder mumbled. "Just thinking about those kids..."

Scully said nothing. After the previous afternoon, she didn't want to try to remind him it was over.

Fortunately, the phone rang. Mulder answered, and after a moment turned to look at Scully, shocked. "She asked for us, too?" he said into the phone. "Okay, we'll be right there."

"Who was that?" Scully asked.

Mulder stood and grabbed his coat. "Langly. Byers just got called to the school...Casey's been in a fight. She asked for us as well." He tossed her coat to her, and opened the door. "Let's go."

Scully contemplated on arguing, but decided against it. She and Mulder headed out the door to the parking lot.

Cedar Grove High School

4:30 p.m.

Mulder and Scully arrive to see the end of the "parent/teacher conference" with Byers, Casey and the principal. Byers exited the office, looked distraught. "She wants to talk to you," he muttered, indicating Casey.

The two agents went in. Casey sat, still in her street hockey gear, in the conference room. Her head was hung, her shoulders slumped. Feeling a bit uncomfortable with the high emotions attached to the recent incident, Mulder decided to let Scully handle the interrogation while he talked to Byers.

John Byers sighed as he and Mulder made their way into another room. He seemed to have aged years in a matter of minutes.

"When her parents come home, and find out what happened..." Byers trailed off.

"It's not your fault, though," said Mulder. "I'm betting it isn't even her fault."

"It doesn't matter, Mulder," Byers said, exasperated. "Her parents will blame me. They'll say that I put these ideas in her head. She'll be in so much trouble, getting suspended for fighting. And I'm worried that the police might hold her for how violent a fight it was."

Mulder nodded slightly. He understood how hard it was, in both cases. But he still believed there was another explanation, one that would clear Casey and the other five kids involved in the similar incidents. "Did Casey have anything with her? A backpack, purse, whatever?"

Byers nodded towards the nurse's office. "They're keeping the stuff she had with her in there. Police have already gone through it, and thank God they didn't find anything to get her in more trouble."

"Mind if I have a look?" asked Mulder.

"Help yourself."

Mulder entered the empty nurse's office, briefly noting how similar it was to the one from his old high school. He saw Casey's mesh backpack and Nike sports bag sitting on a chair. The police were right, he determined as he searched the bags, there was nothing there to explain her rash behavior. Mulder was just about to leave when he saw Casey's water bottle tucked away in a half-open zippered pocked. He pulled it out, unscrewed the lid, and looked inside. There was a small amount of liquid in the bottom. Mulder stuck his nose closer and sniffed, smelling a faint trace of chlorine.

It only took him a moment to come up with a theory, but he knew he couldn't find the truth alone. He ran back to the conference room to find his partner.

When Scully had entered the room where Casey was being kept, she couldn't help but note the girl's body language was screaming "guilty." Head down, shoulders slumped, no eye contact...the true criminals Scully and Mulder had seen over the years usually had this type of poise after being caught. "The benefit of the doubt," Scully reminded herself before pulling up a chair in front of Casey.

"Hi Casey," she said softly. "You remember me?"

"Yeah," Casey muttered. "Where's Mulder?"

"Talking to your uncle, outside." Scully paused a moment to chose her words carefully. "You want to talk about what happened this afternoon?"

Casey let out a shuddering sigh, and looked up at Scully with tear-filled eyes. "I...I don't know. I really don't," she whispered.

"Do you remember?"

"Yeah...but it was like it wasn't me...like I was watching myself from somewhere else," Casey turned her attention towards the tiled floor.

Scully looked through the second of the two records Mulder had given to her in the car, the one on William Akely. "Bill Akely, same age as you, played on the same street hockey team. How long have you known him?"

Casey shrugged. "Just this year. We met through hockey."

Scully paused, choosing the wording of the question carefully. "Your coach, as well as other teachers, reported a sort of 'trash talk' between the two of you. Nothing threatening, nor vulgar, but nonetheless...did he ever give you any reason to be angry with him?"

Casey shook her head vehemently. "No. Bill is...was my friend. Yeah, we goofed around, but deep down," her voice got softer, "I knew he really liked me. And I liked him. We never said anything to hurt each other...it was just 'one-upmanship,' you know?" Tears fell from Casey's eyes as her voice broke off. "I'd never do anything to hurt him, never." She looked pleadingly into Scully's eyes. "You gotta believe me!"

Scully out a comforting hand on her shoulder. "I do. But we have to find something to give everyoneelse a reason to believe you...and the other five kids."

At that moment, Mulder opened the door. "Scully," he said in a hurry, "I think I've found something."

Scully walked over to her partner, who handed her Casey's water bottle. "I talked to Byers, he said Casey takes this and drinks on it during the day. It's usually filled with water from home, but smell this," he pointed into the top.

Scully did so, and frowned. "It has a trace of chlorine."

Mulder nodded. "School water. They put chlorine in there to kill germs." He turned to Casey. "Did you fill this up at the water fountain today?"

Casey nodded. "This morning."

Mulder walked over to her. "Did you at any time during the day feel sick, or not like yourself?"

"Around sixth period I started feeling dizzy and weak. Then I got a migraine and my vision was blurry. I thought I was feeling better when practice started."

Mulder turned back to Scully. "I want you to run a lab test on that water. See if there's anything unordinary in it. I'm gonna stay here and keep an eye on Casey and Byers."

Scully nodded. "I'll call you when I get the results."