A/N: So this is something that has been going around in my head for a while. I really wanted to do a crossover fic of my two favourite shows and this is the result. I really hope you like it, and reviews are always welcome.

Disclaimer: I don't own either of these shows. This is just my way of paying homage to them.

January 18th 2005, Chestnut Hill, Philadelphia.

"Hey Lucy, you wanna come over?" her best friend asked her as they were walking home from school.

"Can't today, I've got loads of homework to do and there's a test tomorrow. I need to study. How about tomorrow?" Her best friend smiled and nodded. She knew that Lucy Austin studied hard, and was one of the brightest people she knew. The two of them continued on their short walk home and parted ways some minutes later, each heading off towards their own houses. Lucy was feeling good. Her life was pretty much going the way she had planned, she was top of her class at school and was already planning out her future career as a Criminologist.

Not too long after she had said goodbye to her friend she had finally arrived at her house. She opened her front door and called out to her sister. "Carla? Are you home?" She walked into the kitchen but there was no one there. Thirsty, she grabbed a bottle of soda from the fridge and set her school bag down onto the dining table, noticing Carla's own bag lying against a wall. Their parents would be home for another couple of hours so it was just her and her older sister in the house. She casually walked up the stairs towards her sister's bedroom. "Hey Carla, I borrowed your blow dryer this morning, couldn't find mine. Hope you don't mind." She didn't get an answer from her sister. As she approached Carla's room she saw that the door was open. "Carla? Are you okay?" She crossed the threshold and stepped inside. The sight before her made her drop the bottle from her hand, soda spilling all over the beige carpet. "Carla!" There before her on the bed lay the body of her sister, covered in blood. She could feel the tears welling up behind her eyes as she rushed to Carla's side. One hand holding her sister's hand, the other hand desperately trying to find a pulse, but when she could find one she fell to her knees on the floor, bursting into uncontrollable sobs. She stayed liked that for about a minute before reaching into her jeans pocket for her phone. She tried to take it out but it slipped onto the floor as her hand was now also covered in blood. Trembling now, she picked it up and dialled 911. After telling the person on the other end of the phone what had happened she hung up, dropped the phone to her side and cradled her dead sister's body in her arms, tears now streaming down her face.

….

Present day. PPD Central.

It was nine o'clock in the morning when John Stilman walked into the bullpen and towards Lilly Rush's desk where she sat sipping her morning cup of coffee. "Hey Lil, can I have a word?" he quietly asked her.

"Sure, what's up boss?"

"Not here, let's go somewhere more private."

She nodded and the two of them headed towards one of the interrogation rooms. Once inside, Stilman gestured for Lilly to sit down and he did too. "What's going on?" she asked, a touch of concern evident in her voice.

"We've just got word of a murder last night." he began, a solemn look on his face. "He was a cop." Stilman took a breath "Jeffrey Fallwood." His gaze moved to Lilly who had, up until that point, been sipping her coffee. Upon hearing that name she froze, a mixture of quiet shock and horror filling her mind. "I'm sorry Lil," he told her, his voice now more gentle. Lilly nodded and swallowed before asking, "What happened?"

"He was found in his apartment," he paused, "his throat had been cut." He almost whispered. Lilly could feel the tears begin to well up behind her eyes but she refused to let them fall. "I thought you should know, I know you two were close."

Lilly just nodded her thanks but just as Stilman got up to leave Lilly asked, "Who's handling the investigation?"

Stilman turned around to look at her. "I pulled some strings and managed to persuade them to let us have it." He paused, "Lil, you know that you can't touch this one. You were too close to the victim."

Lilly nodded in understanding, "can I at least have a look at the file?"

"I don't think that's a good idea." Stilman cautioned. "I haven't seen the actual crime scene but I'm told it's quite…disturbing."

"I need to see how he died." She told him, her voice had dropped to almost a whisper now.

Stilman thought about this for a few seconds before giving in. "Okay."

….

About an hour later Scotty Valens and Kat Miller had just gotten the case file and had begun to pour over the notes. "Is this the Fallwood case?" Lilly asked as she walked over to them.

"Yeah," Scotty replied and then looked at her, "listen Lil, we'll catch whoever did this."

Lilly nodded her silent thanks. "Are these the photos from the scene?"

"Yeah," Kat told her. "You sure you wanna look at those Lil?"

"I'll be fine." Lilly said attempting a reassuring smile but not quite pulling it off. There were five photographs altogether; Lilly looked at the first one and had to fight the nausea that threatened to overwhelm her at the sight of her friend lying on his living room floor, in a pool of his own blood, his throat slit.

"I'm sorry Lil," Kat told her softly, full of concern for her colleague.

Lilly slowly set that picture aside as she began to examine the second one. "Looks like there was a struggle." Lilly said as she looked at the photo of Fallwood's dishevelled living room. "Broken furniture…." Lilly paused, "is that blood on the wall?" She squinted at the corner of the photo. "Doesn't look like spatter…"

"Yeah, there was something drawn on the wall." Scotty informed her. "There should be another picture of it in there."

Lilly flipped through the remaining three photos until she came across the one Scotty was talking about. The nausea threatened her again as she looked at the red smiley face that was staring back at her in the picture. "What kind of sick bastard would do this?" She asked to no one in particular. She looked at it again and a thought occurred to her. "Wait, this whole thing looks familiar."

Kat looked at her, "what do you mean?"

"I think I've seen this before." She picked up the photo of Fallwood's mutilated body again and looked at it more closely. "It was on the news. There was a serial killer in California who had the same M.O.; a red smiley face on the wall."

"I think you're right," Scotty agreed and then proceeded to Google it on his computer. A few seconds later he found what he was looking for. "Hey, come and have a look at this." He asked his two colleagues who gathered round his desk. "His name was Red John. He killed his victims by slitting their throats and then painted the face on the wall with the victim's own blood!"

Lilly's eyes widened in realisation, "You..you don't think that….that was his blood? Oh God!" Another wave of nausea washed over her and she ran off to the toilets. Kat exchange a brief look with Scotty before following her.

"Lil?" she called out as she entered the ladies room. "Lil, you here?" she got her answer when she heard the blonde detective throwing up in one of the stalls. Not long after that Kat heard the toilet flush and Lilly emerged, looking slightly embarrassed. "It's okay Lil," she began, sensing her embarrassment. "We're trained to be detached from all this… but it's different when you know the victim." Lilly nodded, and then moved to the sink to splash some water on her face. "You okay?"

"Yeah, it's just…seeing him like that! I…I just spoke to him last week."

Kat put her hand on Lilly's arm, a gesture of comfort and understanding. "I know Lil, I know."

Once Lilly had finished washing her face, she and Kat walked back into the bullpen. Upon hearing them enter, Scotty immediately met Lilly's eyes, worried for his partner. Lilly smiled and went over to his desk to see what else he had found. "This is strange," Scotty began and his colleagues once again gathered round his computer. "It says here that this Red John was killed, not too long ago."

"So you saying this is a copycat?" Kat asked.

"Looks like it." Scotty sighed and leaned back in his chair. "A good one. The way this whole thing has been done is very similar to the original Red John murders. Whoever did this really knows their stuff."

Intrigued, Kat nudged Scotty out of the way and took over the mouse as she scrolled further down the web page. "It says that this guy had followers… you don't think whoever did this might kill again?" she asked.

The three detectives looked at each other, silently coming to the same conclusion. "We've got to fine the person who did this or we could be looking at our own version of Red John right here in Philly!" Lilly said, once again looking at the sickening crime scene photos.

"It says that the team handling the original case was the major crimes unit of the California Bureau of Investigation, headed by an agent Teresa Lisbon." Kat noted, "Maybe we should give this agent Lisbon a call? She might have some useful info for us that may help us find Fallwood's killer?"

Scotty nodded, "I'm on it." And he proceeded to dial the number. The female detectives went back to their desks, giving him some room. After forty minutes of trying to contact her he was finally able to get through.

"This is agent Lisbon." Came a female voice from the other end of the line.

"Hi, this is detective Scotty Valens from Philadelphia homicide. I understand that your team was in charge of investigating the serial killer Red John?"

There was a brief pause "that's right. How can I help you?"

"We had a murder last night, a cop, same M.O. as your guy. We think we have a copycat on our hands and we were hopin' you could provide some insight into him that might help us with our investigation?"

Another pause. "Agent Lisbon?" Scotty said, wondering if she was still there.

"Sorry, off course detective Valens. Whatever we can do to help. I'll have someone send you the Red John profile and whatever other information you need…sorry could you please hold for a second?" she asked.

"Sure, no problem." Scotty replied. There was a few seconds of silence before he could hear her arguing with a man. He smiled to himself, realising that in her haste she had forgotten to mute the line.

"I' m sending them the files….no we can't…no… Jane…..Jane!"

Before he knew what was happening, another voice greeted him on the phone, a man's voice, no doubt the same man agent Lisbon had just been arguing with. "Hi this is Patrick Jane, I work with agent Lisbon. I understand you think you might have a Red John copycat?"

"Err..yeah that's right. We think whoever did this might kill again, any help you could give us would be greatly appreciated."

There was yet another brief moment of silence, which made Scotty think that he might have been put on hold. "Detective Valens was it? Agent Lisbon and I would be like to offer our services to help you find this killer. If it's okay with you, we would like to come to Philadelphia and work with your people?"

It was Scotty's turn to pause, "errr..yeah, sure. That'd be great!"

"Excellent! We'll see you soon." He then hung up the phone.

Scotty smiled a little to himself as he researched this Patrick Jane on the internet. He certainly seemed like an interesting character and was looking forward to working with raised an eyebrow at the major crimes case closure rate. At least they had the best people to help them. He turned toward his partner who was sat at her desk, her head in her hands, still staring at the crime scene photos and his smile soon faded. Don't worry Lil, we'll find the son of a bitch who did this! He thought, feeling a sudden sense of protectiveness towards her as his fist clenched. He'd been working with her for many years, they had been through so much together and yet he had never seen her so vulnerable as she was at that moment. He swore to himself then and there that he would make this right.