Title: The Unknown Threat

Disclaimer: I do not own Criminal Minds

Summary: A new danger in closing in on one of their own. While investigating a new string of deaths, truths with come out. Sequel to "The Mysterious Dr. Reid" and "Physics Magic…Bullet".

A/N: Hey guys! Oh my goodness, the responses. You guys are amazing. Thanks to Coffee Kitten, , CMSP, eliana152, bookgeek, and TheeKozakura for the great reviews. I know I said a week, but I've kind of gotten hooked on the idea in this story. So...here is the next chapter. I really hope you enjoy. Please R&R.

Chapter 2

"What does this mean?" Rossi made the mistake of asking the question in the presence of their walking encyclopedia.

Without blinking Reid answered expressively, "The symbol itself is known as a lemniscate. The idea of infinity has existed since the thinkers of ancient Greece. In fact, the word infinity comes from the Latin infanitas which means 'unbounded' or 'endless'. It was popularized in modern mathematics and physics in the 19th and 20th centuries by Georg Cantor who introduced the idea of cardinalitie—".

"Reid!" Morgan snapped him out of his rant.

Reid shut his mouth quickly, looking at his shoes, "Sorry."

Rossi was undeterred, "I meant what does the symbol mean in this case?"

"Maybe it was a message to someone," JJ answered.

Reid nodded, "It could be. Though there are many meanings, the unsub could possibly mean they or some process cannot be stopped." The team continued to think as the crime scene workers moved about them, collecting evidence.

Hotch directed their next move, "Reid I want you to look around the scene here. See what you can find." The team knew this made the most sense as the young doctor could likely relate to the man.

"I'll work the scene with Reid," Morgan spoke up. He always hesitated to leave anyone at a crime scene alone.

"Fine. Prentiss and I will look over the files for the first case. Rossi, I want you to meet up with JJ at the university. Talk to his colleagues, his students. Find out if anyone had a reason to hurt him. I'll have Garcia look into Dr. Welch's past, see if he has any ties to our first victim. Also see if there is any relevance to the symbol carved in the bodies," Hotch looked around at his team as they nodded in affirmation.

Reid added, "Have Garcia also see if either victim had any ties to gang activity or even mob activity."

Everyone looked at him, apprehension on their faces. Morgan asked, "You think this may have been a hit?"

"I don't know, but they were organized and quick. We also know they are unified somehow by this symbol. I think we need to just cover all our bases," Reid replied.

"He's right. We need to look at this from all angles," Hotch then directed Prentiss toward the exit and down the hallway. Rossi followed behind, leaving Morgan and Reid to survey the apartment with the scattered CSU workers.

~CRIMINAL MINDS~

Several hours later the body had been removed and Morgan left the bloody living room to find Reid in a small crowded room in the back of the apartment. The young genius sat hunched over a cluttered desk flipping through a tattered notebook. He bore an intent stare that expressed things Morgan would never understand. Sometimes he wished he knew some of the things that floated through Reid's head.

"Find anything useful?" Morgan asked.

Still slightly distracted, Reid answered from behind the pages he was still scanning, "I'm not sure. I've been through everything in here. There is nothing to really indicate that he was involved in any type of organized crime. All I have found are things related to his work through the university, lesson plans, and some side physics exercises." Morgan could feel that Reid was not finished.

"But…"

"But there is something about this notebook," Reid answered quietly.

Morgan leaned over to glance at the pages. It looked like gibberish to him; simply a bunch of symbols and numbers. Confused he asked, "What?"

Reid answered carefully, unsure himself what it meant, "This seems completely unrelated to all of his other work. Notice how the notebook looks neglected and unimportant. To me that makes it stand out, like he didn't want it noticed. The work in it seems directed," he thumbed through the pages for the hundredth time, "But he has it so scattered, it is difficult to make any sense of it. I feel like I have seen this before, but not quite like this."

"You know what all this mean?" Morgan asked incredulously.

Reid actually looked up from the papers, "Morgan I do have a doctorate in engineering and mathematics."

Oh yeah. How could I forget that one. Morgan chuckled, "You never let me forget."

Morgan continued, "Does it actually help us?"

"Not sure yet."

Sighing in frustration, Morgan leaned on the end of the desk, "Well, I don't have much either. The guy was a loner. His whole life was his academic career. No family. Not many pictures. Just lots of books." Morgan chuckled a bit, "Kind of reminds me of your place."

Reid didn't return his grin, still caught up in the mystery.

"You doing okay kid? You look tired," Morgan commented, remembering that Reid had walked in from his second office and most likely had been working on some of his "contract work" the night before.

Reid raised his eyes to look at Morgan finally, "What?...Oh, yeah I'm fine. Just some data came in that was needed right away. Just helping with some number crunching and scatter locations." Morgan was surprised he was sharing so much.

"Ok, Trip," Morgan said smiling, both men starting to make their way toward the front door. "Let's go see if anyone else had any luck."

Turning red at his gunslinger nickname, Reid answered, "Stop calling me that or I'll have to show you that I can kick your ass in other ways than just at the shooting range."

They both chuckled as they walked out the door, but Morgan silently cringed as his realized that Reid might not be joking.

Yay, another chapter. Thanks so much to everyone who is following this story. Hope to give you more soon! :)

~M~