KATHARINE FIGURED THERE WERE SOME SICK PEOPLE OUT THERE, but never in her eight years of being an agent, has she seen anyone drown another person in methanol. Sure, the closest she's gotten to that would be acid, but at least that was within the normal parameters of torture.

But methanol... nope.

Katharine watched as Spencer worked, occasionally handing him a piece of tape or a pen as he talked to himself. Truly, what she had told Seaver was the truth. While she was a decent profiler, her talents lay in apprehending the bad guys and knowing way more than she should about killing a person with a ballpoint pen.

And, admittedly, she was still learning. So far, she had been able to get by on hunches that turned out to be correct and any and all knowledge that she could practically absorb from Spencer. He'd prattle off a fact or statistic and because it was him, they all seemed to stick.

She crossed her legs and set her tablet down on the conference table in exchange for one of the victims' files, reading through the life of Vickie Hagerg and trying to see if anything about her could be useful to find the guy who killed her.

She read through twice, finding that she was an overall average person. Katharine frowned and picked up Shelly Onto's only to find the same thing in hers and Linda Dean's. Not only were they completely average and seemingly unconnected, but they were all purely victims of opportunity.

Spencer came barreling back into the conference room, marker already in hand as he started spewing out what he had learned from his phone call with Garcia.

"Guys," he said. "As I feared, methanol can be easily purchased from any chemical supply house in Southern California. It's not controlled. You can buy it in large quantities or small quantities."

He uncapped the marker and started drawing on the clear board they had been given to use. "Now, I've charted the abduction and disposal sites. Linda Dean was taken from Hollywood. Her body was dumped in Echo Park. Shelly Onto was last seen in the garment district. Her body was dumped in Sherman Oaks. And finally, Vickie Hagerg was taken in Torrance south of the city. Her body was left in Westlake."

Katharine observed the points Spencer had marked off and frowned. The three points were so far spaced out she'd have to drive to get from one point to another.

"It's a huge geographical area," Hotch said.

"The only area the unsub hasn't hit yet is east of downtown," Spencer highlighted, "which means we can either eliminate it or it's the one place left."

"So we're back to nothing," Rossi sighed.

"No, not necessarily," Spencer turned around and rummaged through the photos that were spread out across the table. "I looked at the crime scene photos. These sites are true dumpsites. I mean, there's no concealment, no staging. He literally just dumps the bodies there like garbage once he's done with them."

"The randomness could be orchestrated or it could simply be opportunity," Hotch said. Katharine slid one of the photos in Spencer's direction. "Either way, he's very mobile."

"All of the dumpsites, including the most recent one, are between the one-ten and four-o-five freeway and the five and ten north and south," Spencer said, circling the spots on the map.

"Linda Dean's family said she always took the Red Line home from work at night, but the subway in LA Stops running at one am," Emily told them. "She clocked out of work at five past one."

Katharine tapped the end of her pen against the table. "LA at one am? She probably didn't walk home."

"No," Emily agreed with her. "And Kingsley's a mile away."

"All the victims had breathed an aerosolized chloroform," Hotch said, looking up from the ME report. "And to do that he needs an enclosed space."

"You know, chloroform's a lot more controlled than methanol," Spencer said, already taking his phone out of his pocket. "I'll have Garcia track any large quantity purchases or thefts from chemical supply houses."

"So we're looking for a vehicle, one that could be in any area of Los Angeles at one in the morning and not attract attention," Emily said as Spencer left the room to make his call.

The detective on the case frowned. "I hate to say it, but that could be a police car."

Katharine sighed. She picked up Linda Dean's file once more, flipping through it.

"Or a taxi," Katharine said, getting up from her seat. She made her way out of the room and found Spencer quick enough. She settled onto the desk in front of him and waited patiently for him to stop talking.

"Can you ask Garcia how many cab companies there are in LA?" Katharine asked, tapping her fingers against the desktop. "And ask her to call Derek back with that answer, please."

Spencer nodded, relaying her message to their techie before hanging up, thanking her for her help.

He hung up the phone, resting his bent arm over Katharine's lap and propping his other elbow up on the desk. He rested his head on his open palm, looking up at the light-skinned woman.

"What's up?" he asked, tapping his fingers against the outside of her thigh.

Katharine shrugged, taking the time to run a hand through his hair. She messed it up a little, causing Spencer to swat her hands away from his already-messy locks.

"You're just really beautiful," Katharine said, admiring her boyfriend. His face flushed red as she got up from the desk, taking his hand in hers and tugging him back toward the conference room.

They reentered the room together, Katharine letting go of his hand once they were in sight of their coworkers. She winked at him before making her way over to Emily's side, taking up a stack of files Emily was balancing.

"There are seven companies," Derek told the group, returning from his call with their technical analyst. "Garcia's running them down."

"Good," Hotch approved.

"Most taxis here run out of cab stands," the detective told them. "It's not like New York where they're running all over the place."

Katharine nodded, setting half of the files down in front of Emily and keeping the rest for herself.

"That should help narrow down the choices," she said as Hotch excused himself from the room.

They worked in silence, for the most part, occasionally throwing out an idea or two before returning to the evidence the detective had already gathered. Not too soon after, Hotch had returned to the room and Derek's phone rang. He answered the call, putting Garcia on speakerphone.

"What do you got?" he asked, holding the phone in front of him.

"Ok, I checked all seven cab companies that service the Hollywood and Vermont area, and none of the drivers reported picking anyone up between eleven and two the night Linda went missing."

"And they know that for sure?" Emily asked, furrowing her brow.

"Yeah. They seemed really certain."

Katharine bit her lip. "Well, one of the drivers may have picked someone up off the meter."

"The cabs have GPS?" Hotch asked.

"Yeah. Taxis are tracked more than Gaga's Twitter."

Katharine laughed at Garcia's little comparison, her amusement only growing when Spencer asked, "What does that mean?"

Rossi leaned over the table toward the phone in Derek's hand. "I'll explain it to him, Garcia."

"Yeah, teach him to worship the other Lady G, boss. Ta and ta."

Emily sighed, closing one of the files she had open in front of her. "So there were no taxis in the area."

Rossi stroked his chin.

"What about a gypsy cab?" he pondered aloud. "They roam around in unregistered vehicles with fake insignias that look legit."

The detective shook his head. "There are two-thousand, three-hundred registered cabs in the city and at least as many unregistered."

"And no one pays any attention when they get into a cab," Rossi said in resignation.

"If he's unregistered, he's not gonna sit outside taxi stands and wait to pick up fares in the traditional way," Emily said, also in resignation. In the words of Penelope Garcia, this would be like finding a needle in a haystack.

"Which makes him even harder to find," Derek said. "This guy could be anywhere."

"Detective," Hotch addressed from his spot at the head of the table, as always. "Can you gather everyone? We'd like to give the profile."

The detective agreed and Hotch thanked him before he left to gather the rest of his crew. Katharine set to reorganizing their evidence, looking through everything once more before holding up one of the photos of the girl's feet with the square of flesh cut out from the bottom.

She practically flew over to Spencer, handing him the photo.

"Listen," she said, showing him the photo. "I know I'm not Simmons but what would the unsub be doing with square samples that are two by two?"

Spencer took hold of the photo and scrambled for the other two photos of the feet that they had.

"What is it, Reid?" Hotch asked.

"Katharine's right," he said, pulling up the two other pictures of feet. "When I was in school, we used to use methanol to separate chemicals from each other. Whatever we did, we'd clip a sample of the source material to label and keep next to the output."

"What kind of samples?"

"Square samples two inches by two inches," he confirmed Katharine's thinking. She knew constantly hanging around Simmons in the lab would eventually pay off. "I think this guy's a scientist and he's experimenting."

"WE WANTED TO GET A PRELIMINARY PROFILE TO YOU AS SOON AS POSSIBLE BECAUSE OF THE TYPE OF UNSUB WE'RE DEALING WITH HERE," Hotch addressed the station, standing at the front of the room. To his right stood Rossi and Emily while the rest of them had lined up on his left.

"We believe he's a male caucasian, driving an unregistered gypsy cab," Rossi said. "He uses the vehicle to abduct the women."

"His victims have been between the ages of twenty and forty," Katharine presented next, "and we think that he's in the same age bracket."

Spencer spoke next, Katharine turning her head to her left to look at the man. "Add to that his use of methanol for whatever reason and the aerosolization of chloroform, and we believe that we're looking for a very intelligent unsub."

"Which is not unusual," their boss said. "True psychopaths often have above-average intelligence."

"This type of unsub will not have injected himself into the investigation as we often see," Emily spoke next. "He will not be following the investigation very closely. In fact, he may not even be concerned about whether he's leaving any evidence."

"So how come we can't find him?" the detective asked, obviously frustrated with how the investigation had been going so far.

"Because of what he's doing to them," Spencer told the man. "He's submerging them in liquid, which is washing away any forensic evidence which might be there. And then he's wrapping the bodies in plastic."

"There is something about him which will be helpful," Katharine said, moving her attention away from the detective. "He's extremely antisocial. We've all heard neighbors say after an unsub is caught how surprised they all are. That will not be the case with this guy."

"Couple his explosive, antisocial nature with taxi-driving and someone will have made contact with him," Rossi said. "They will remember."

"We suggest going public with the information as soon as possible," Hotch recommended. "That he's an unregistered taxi driver and that he's had confrontations with people in the city. Thank you very much."

Katharine nearly jumped as multiple pagers and cell phones went off, which shocked her almost as much as the initial scare. The last time she had been so prone to devices suddenly going off was the entire year she had to take off. She was the jumpiest preschool teacher there ever was, always looking over her shoulder just in case someone was following her.

Honestly, she didn't miss it. Being constantly on edge didn't help her nerves and it certainly didn't make her life any easier. If anything, it made her paranoid and untrusting of anyone within a ten-foot radius.

She tried to reassure herself that there wouldn't be an assassin lurking in her window. After all, she only had so many bullets and she couldn't afford to be shooting windows left and right. At the end of the day, she was still only a government employee on a government paycheque.

Hotch filled them in. Another body had been found. He gave his orders, telling Derek to get onto the air with a statement for the press while Spencer and Katharine would stay at the station in case any new information came in while everyone was out on the field.

Katharine didn't complain. She just gave her boss two thumbs-up before retreating back into the conference room with Spencer.

AFTER FIGURING OUT THAT THIS PARTICULAR UNSUB'S TRIGGER WAS SMELL, they were able to figure out pretty much everything about their guy with the help of the amazing and wonderful Penelope Garcia.

"We have an address," Spencer told Katharine, throwing her the keys to the SUV Hotch had left them. She quickly threw on her jacket and made her way to the vehicle sitting outside waiting for them.

She turned on the sirens and flew through the streets, Spencer telling her where to go at every intersection.

Soon enough, they arrived at the scene barely five seconds after the rest of their team had arrived.

"Morgans and Prentiss, take the back,'' Hotch ordered as soon as they got out of their vehicles. Katharine tied her hair up quickly before unsheathing her weapon, coming up behind Derek as they crept toward the back of the house.

She heard Rossi say, "He's got eyes on us," over the comms before headlights flooded her vision.

"He's running!" Derek called, running back toward the SUVs. Katharine ran back to her's, not waiting for anyone else before tearing away from the house and driving as fast as she could after the man.

She took the lead in the chase, seeing both Hotch and Derek swerving behind her.

Katharine cursed as their unsub decided to take to the highway, blaring the sirens as she continued their chase.

Her eyes widened as the taxi took the next exit, taking a sharp right down a one-way street. The taxi had managed to get ahead of them, slipping in between the concrete barrier and a truck in order to get away from them.

When the truck moved out of their way, Katharine cursed again when she had realized the guy had managed to escape.

"We lost him," Katharine said over the comms. She could hear Derek curse over the comms as well. 

"Split up," she heard Rossi tell her. She nodded and took to the right while Derek went left and Hotch went straight.

She carefully scoured the area, flashing her high beams in order to see better. It wasn't long before Hotch radioed them in to let them know their unsub had driven his taxi straight under a truck, taking off his entire top half. Katharine pulled over to the side, resting her head on the wheel.

She heard Hotch order them back to the station, to which she sighed before pulling away from the curb and heading back.

"REID?"

"Emily, you are not going to believe this," Spencer said, packing his things away.

"No?"

"They're showing 'Solaris' tonight, the original, in the theaters," he told the woman, moving between his desk and Katharine's. He had offered to take up half of her paperwork and was just finishing for the night. "You want to go?"

"Did Morgan put you up to this?"

"What?" he asked, almost laughing at the thought.

"Did Morgan tell you to call me?"

"No," he said, shaking his head. "Morgan would have no idea what 'Solaris' is."

"So, uh, you just called me out of the blue."

He opened one of Katharine's drawers, replacing the pens she had allowed him to use. "Well, I mean, the original one's in Russian, so, really, you and I are the only ones that can really enjoy it. Besides from Katharine, but she's already on her way to New York to see Nina."

"Isn't 'Solaris' like four hours long?"

"It's five," he said, closing the desk drawer and locking it up. "The best Sci-Fi meditation film of all time. But for some reason, they never really show it in the theaters. You want to go with me?"

"Sorry, handsome. I'm gonna have to pass," Emily excused herself. "I'm just gonna hang out with Sergio tonight."

"Oh, shoot. I didn't realize that..."

"Relax, Reid," she said. "Sergio is my new cat. But, um... Thank you."

"For what?" he asked, one hand in his pocket.

"For being you."

"Aw, thanks," he said, slinging his bag over his shoulder. He pushed his own office chair in, taking up the keys to Katharine's car. "I don't know how to be anyone else."

"Yeah. That's what I love about you," Emily said. "Bye."

Spencer responded with the same before leaving the bullpen. He'd go see Solaris on his own if he had to. He made his way to the car, throwing his bag into the passenger seat before getting in himself, adjusting the seating before turning on the car.

He smiled to himself as he pulled out of the garage, tapping his fingers on the steering wheel as Katharine's playlist filled the night air.