A/N: Yes, you see right. I really did it. I tried myself on a crossover between The Mentalist and Castle. Because I love both shows. And because I totally got inspired by yaba's "The Rules of Every Successful Merger" and both of waterbaby134's stories "It Takes a Village" and "Scratched". If you don't know them, go and read them. They're awesome!

This story takes place somewhen after both Season 4 finales, but from there on it's all my imagination. And I really don't need to tell you more, because everything else will be explained within the story. I also decided to post the Prologue together with the first chapter, because somehow I felt like the both should stay together ... I don't know. Also, this is my first attempt in writing for Castle and - quite frankly - it doesn't come that easy to me. Therefore I'm afraid this will contain more Mentalist than Castle, for I just feel more comfortable writing them. But be assured that I try really hard to give everybody their fair share. ;)

That's all, folks. Thanks go to my awesome beta Kassandra (Thank you for you constant encouragement! I couldn't do it without you!), to all my reviewers and readers of previous stories, and to all those awesome authors out there who save me day after day by providing the much needed reading material. This is to you, guys!

And now: ENJOY! ;)

Disclaimer: The Mentalist and Castle belong to their respective networks and creators. Nothing related to them is mine. This story was written purely for fun. No money, no copyright infringement, no nothing.

COLLIDING PATHS

Prologue

They just closed a case. A very nasty one, so to speak, and all of them were relieved when the handcuffs were secured around the killers wrists.

Jane had just made some joke about Rigsby nearly falling all over his feet whenever it came to showing off new pictures of Benjamin, and all of them (except for Rigsby of course) joined in the laughter. A minute later she finished off the last bite of their after-case-pizza while returning to her office to work on the paperwork, when her phone rang and a familiar area code flashed on the screen. Still smiling she picked up, pronouncing a short, Lisbon.

Only a heartbeat later her smile was gone. Serious, controlled, tough-as-nails Senior Agent Teresa Lisbon surfaced, nodded a few times, asked short questions like "When?" and "Who?" and "Why?" every once in a while, before she confirmed with "I'm on my way." Afterwards she snapped her phone close and passed her own office on the way to Julian O'Neilley, Luther Wainwright's replacement as CBI chief after the latter was killed in their last show-off with Red John a few months ago. O'Neilley reminded them a lot of Minelli.

While the other agents fooled around and had fun, not even realizing the strange behavior of their boss, their consultant had curiously watched her every move. His concern increased after he discovered her serious face and then her storming off in the direction of Julian's office. What had happened?

Not five minutes later she hurried back and stopped in front of them with the words "Guys, I need to talk to you."

If he was worried before, now he was panicking.

oOo

His wife had just called and threatened (with a smile nonetheless) to sell his favorite Stones LP, if he didn't make it home for dinner by seven, and he was still playfully debating with her, when a short knock was heard and a moment later Teresa Lisbon stood in his office.

The introduction of his little girls boyfriend (okay, she was 23, so maybe not that little anymore) immediately lost his interest when his eyes fell on the determined expression on the agents face. He told his wife that he would call her back and then turned to the woman standing in front of his desk.

"Agent Lisbon, how may I help you?"

"I'm sorry, Sir, for interrupting like this, but this is kind of an emergency."

O'Neilley sighed. He may not have been CBI chief for long, but he had already heard enough stories including Agent Lisbon and her team. Especially stories about her more than unconventional consultant and the problems he loved to cause.

"What did Jane do this time?"

A small smile crossed her lips, but a blink of an eye later it was gone again.

"Surprisingly this time it has nothing to do with Jane."

And with these words he pricked his ears.

oOo

24 hours later Teresa Lisbon stepped through the sliding doors of JFK International Airport in New York, hailed a taxi, and told the cabbie where to go. She had a suitcase with her, plus a bottle of tequila and a box full of Swiss chocolate, and minus a badge and a gun.

Chapter 1 – There's always a before …

New York Police Department Police Academy, July 2000

She had decided not to continue her law studies at Stanford, but instead – as silly as it may sound – she joined the Police Academy. And she really liked it.

Of course it was rough. Wake up at 5 a.m., lights out at 10 p.m. sharp. The days were filled with academics and physical training, with human relations, law, and tactics. Driving. Firearms.

And Kate loved it. It was her second month here and right from the beginning she felt that she had chosen the right thing for her. Every day brought her one step closer to the goal of finding her mother's killer. In only six short months her training would be over and then she would join the NYPD.

The door to her dorm opened and in stepped recruit Lisbon. Or her friend Teresa, as she was known after the drill of the day had ended.

Teresa had started her training about a month earlier than Kate, joining NYPDPA after finishing her undergrad studies in criminology and human behavior at Chicago State. She was two years older than her, and constantly worrying about her three younger brothers, age 19, 17 and 16, whom she had left for the first time in over 10 years, in the custody of an aunt back in Chicago.

Their lives had so many similarities. Both lost their mother: Teresa to a drunk driver when she was only twelve; Kate to an unknown murderer only around one and a half years ago, when she was nineteen. Both had fathers with an alcoholic past: Teresa had lost the battle, her father killing himself one drunken night when she was only 18 and 'one more drink' was simply too much, leaving her with three younger brothers to take care of; Kate was still fighting the battle, trying everything she could to get her father sober.

They met and instantly liked each other.

"I swear, Katie, at some point Bings will break my neck. There isn't a single bone in my body which doesn't scream out in pain. I'm even too tired to call Greg," Lisbon sighed before dropping down onto her bed.

Beckett grinned and with a sideways glance playfully scoffed, "At least you had physical training today. I had academics and driving. What a bore!"

They looked at each other and started to giggle.

oOo

California Bureau of Investigation, June 2004

She was only 26, a detective only for little over a year now, and already got hired by the CBI. It came a little by surprise, to tell the truth. One Tuesday afternoon, about a week after the McTier case got closed, her phone rang and Chief Agent Virgil Minelli from the CBI asked her if she was interested in a career within the Bureau.

So two weeks later she had all her stuff packed, had rented an apartment in Sacramento, and had a tearful goodbye with her colleagues from San Francisco Police Department. The evening before her move to California's capital city she had a last dinner with Sam Bosco and his family. He was her mentor, her friend. Everything she knew about police work, she knew from him.

And now she was here: Junior Agent Teresa Lisbon, CBI. It still sounded strange, even to her own ears.

When she first told Kate about it, the younger woman nearly screamed her ear off in excitement. Katherine Beckett may still worked as a regular Police Officer at the NYPD, but both women knew that it would be only a matter of time for her to get promoted to Detective. Rumor had it – as Kate had told her – that Connelly from the homicide department at the 12th Precinct was to retire the next month and that his second in command, Roy Montgomery, was to take over. Resulting in an open spot at the homicide unit. Rumor also had it that Kate was most likely to get that spot, together with the before mentioned promotion.

"We will see how it works out," she told her friend over the phone one Saturday evening, "But enough of all the if's and when's. Tell me all about your first few weeks at the bureau."

And Teresa started to tell her about her new boss, Virgil Minelli, who reminded her so much of her father before he turned to alcohol, and who told her he hired her because he thought she had a lot of potential to be an excellent Agent. About her new unit – at the Serious Crimes department – and her new team, consisting of a Senior Agent in Charge, another Senior Agent and two Junior Agents. She told her about their first case, the murder of a young waitress on a state highway just outside of Sacramento.

"Today Minelli signed up with a new consultant. He will be with Lionel Cooper from Commercial Crimes. We met him today. Wait, what was his name? Something feminine …," Teresa thought for a minute, "… ah, yes. Jane. That was it. Patrick Jane."

"Sounds familiar," Beckett pondered, "wasn't that the name of that TV psychic whose family got murdered last year?"

"Exactly. That's him," Lisbon paused, before muttering under her breath, "Trust me when I tell you that half of his success was solely based on the fact that he can charm the pants off of anyone. No wonder the girls from accounting all swooned when he appeared in the bull pen."

Kate giggled, "And as far as I can remember he isn't bad on the eyes either. Did he charm your pants off you, Reese?"

"Oh, shut up!" Lisbon shot back, but giggling at the same time, before steering the topic away to safer regions. She didn't want to think about the immediate attraction she had for one Patrick Jane. Moreover she didn't even have time for thoughts like that, or else maybe the thing with her and Greg had worked out in the end. And that she didn't want to think about for sure.

"What about you?" she therefore turned the attention to her friend, "Did you meet someone?"

This earned her only a scoff and laugh.

oOo

California Bureau of Investigation, May 2005

"Are you sure, Lisbon?"

"Of course, Sir."

"You know, this may break your neck."

"I'm aware of that, Sir."

"And you still want to take the risk?" he looked confused actually, even a little concerned, "Why?"

Lisbon smiled, "He closes cases, Sir."

And that was it. That was how Patrick Jane came to work for Teresa Lisbon.

The young woman was a miracle. She was climbing up the career ladder like nobody had seen before. Only a little over eleven months ago she had joined the CBI. Four months later she was promoted from Junior to Senior Agent (a first in the history of CBI). And two months ago, after one of the Serious Crimes Unit's Agents in Charge Fisher left them for the FBI, the Bureau (with recommendations from Minelli) decided to promote Agent Lisbon again. Now she was the Agent in Charge of Fisher's old team (another first, also for a woman to head a SCU). The unit consisted of another Senior Agent, Kimball Cho, her new second in command, and a Junior Agent, Wayne Rigsby, freshly joining them from the arson investigation group of the SFPD.

A month into the job she stood in the break room to prepare herself a coffee, when she accidentally eavesdropped on a conversation between the secretaries of Narcotics (Susan) and Emergency Operations (Olivia).

"Livy, he drives us nuts. As cute as he is I can't imagine that anybody can work with this man. He knows no bounds, seriously," Susan huffed and rolled her eyes while telling this.

"You're exaggerating, Susan, I'm sure," Olivia tried to play it down, which only brought her another huff from her colleague.

"Definitely not! We are the fifth unit he's worked with since he joined CBI as a consultant and I'm sure he will soon join his sixth. Jordan told me yesterday that he drives him nuts and that he will talk to Minelli about reassigning Jane. He may close cases, but he certainly has unorthodox methods to do that."

After that Lisbon decided to head back to her office, coffee in hand.

That evening, after she worked through the papers of their latest case, she took Patrick Jane's file and started to read carefully. She took in all the data, read about the tragic occurrence of his family's death at the hands of a serial killer named Red John, studied all reports from the Agents in Charge of all the different units he had worked for by now (and – to be honest – it was quite fun to read. Did he really make a drug dealer confess over a game of poker?), and in the end she looked at his case statistics.

A close rate of nearly a 100%.

When she talked to Kate later that week and told her about all of it, the NYPD Detective assured her.

"If your instincts tell you that this is a good idea, then go for it, Reese. You should trust them; they brought you to where you are now."

"But that's just the point, Kate. My instincts send me mixed messages. On the one hand they tell me to go along with it. That this is a great opportunity. A nearly 100% close rate! I've never seen that before. And on the other hand they tell me that this will most likely be the stupidest decision of my career. Which is it?"

If only she had known …

oOo

12th Precinct of the New York Police Department, April 2007

"Thank you, Sir! I am honored."

"You deserve it, Beckett," Captain Montgomery clarified, "After all, you're one of my best men. No offense."

She smiled, "None taken."

Montgomery nodded, half a smile on his face, and handed over her new badge.

That night at her apartment, while being on the phone with her best friend, a glass of red wine in hand, Kate danced around and felt like she could fly.

"Reese, please let me introduce you to Detective in Charge Katherine Beckett, 12th Precinct Homicide Squad of the New York Police Department. One of the youngest detectives in the history of the NYPD. Very pleased to meet you!"

She laughed and took a sip from the wine, and listened to the praises from Lisbon. 3,000 miles separated them, which made their talks only possible via phone, but that didn't change the fact that Teresa was the first one to hear about news like that, and the other way around. Seven years of friendship and they may have seen each other a handful of times, but that wasn't important. Important was the fact, that although 3,000 miles separated them, they still could count on each other. No matter what.

"Tell me the details! Did that hottie Esposito get signed up with your team?" Nobody else would have got this sentence out of Senior Agent Teresa Lisbon. With Kate it was just different. They never felt like holding anything back. There were too many similarities, too much understanding. They didn't want to hold anything back.

"Aw, of course! But you know that we ended the affair about a year ago. We are friends now. Friends only," Kate clarified, while topping up the wine in her glass.

"Doesn't make him less hotter," Teresa replied chuckling, and her friend joined in.

"So it's me, Esposito, and Kevin Ryan. I think he's Irish. Worked at the 22nd before, has a good reputation."

"Aw, Katie! This is so fantastic! You really deserve … JANE!" Lisbon suddenly called angry, "Do you mind?! I'm on the phone! And I don't want you within 10 yards of me after that stunt you pulled today. Now get out of my office!"

A muffled "You're no fun, Lisbon! I just wanted to take a nap on your couch, keep you a little company. That's not too outrageous, in my opinion. And my stunt solved the case, didn't it? You don't have to be so mean!" was heard, before the Senior Agent growled back, "It also tripled my paperwork. Again! So, out! Now! Delight someone else with your company!"

The woman on the other end of the line couldn't hold back her laugh, before inquiring about this latest stunt of Lisbon's consultant.

"What did Jane do this time?"

The Agent sighed; nevertheless the half-smile was noticeable in her voice, "Don't even ask."

oOo

Over the years they kept in touch, sometimes more regularly, sometimes with weeks in between their last call. Still, they never felt like losing contact, always knew that the other woman was there, somewhere. Knew that the other one understood (they had both quite annoying consultants after all) that no matter what, they were constants in each other's lives.

When Beckett was shot, Lisbon was there. Not immediately after the event, but a little while later, when the support from others was still there, but had already slackened slightly. They took a two-week-trip to Maine, feeling like they were twenty again, when they had spent all their spare time together and were not yet separated for over half a decade. With no care in the world. Two best friends enjoying their precious time together.

When it was the other way around, with Lisbon receiving the bullet in her shoulder, Kate dropped everything and stayed with her friend for a little over a week, ordering take out, getting her to physical therapy, keeping her brothers in check (it was a busy, loud and very crowded week in Lisbon's apartment) which distracted her of the fact that Jane was in prison waiting for his trial.

When Kate was ready to try a relationship with Castle, but he disappeared with his ex-wife for the summer before she could tell him, it was Teresa trying to console her sobbing friend over the phone.

When Teresa couldn't sleep because Jane had vanished for six months, with no word, no sign of life, seemingly breaking down, it was Kate who spent more than one night talking on the phone with her.

Therefore it was the most natural thing in the world that now that Kate had resigned, and hadn't picked up her phone in 48 hours, Lisbon was on her way. She met Kevin Ryan about a year ago when she met Beckett at the station before their trip to Maine, and was really thankful that he had called her now and told her the news.

The two women had worked so hard to get where they were now, this couldn't be it. She needed to talk to Kate, needed to know her motives for such a drastic step.

45 minutes after stepping through the sliding doors at JFK, Lisbon entered Beckett's apartment with the spare key that both of them had for each other's residences (3,000 miles separating them and still they wouldn't give it to anybody else). She had every intention to confront her best friend about her actions when she entered only to find a half naked man in her living room.

TBC