The Why of Pi

Summary: Castle is "this close" to throwing Pi out, whether Alexis agrees with it or not. Beckett convinces her fiance to have some patience and find the root of the problem. (General spoilers for season 6.)

A/N: The major spoiler here is that the DC arc ends next episode, but I'm thinking by now it's pretty much a known fact. Based on that I'm concluding that she's back at the precinct as a detective too. I've also heard spoilers/rumors that the reason Alexis brought Pi home is because Martha told her about the engagement over the phone. I haven't seen proof in any interviews, only saw it on a fan board, so I'm not sure what to believe. It's kind of out there and doesn't make sense when Castle and Alexis are so close, but it got me thinking and led to this story.

Kate opened Castle's fridge and scanned the contents for sandwich fixings. Though she noticed the empty butter compartment and egg tray, she didn't let it distract her from her quest to locate the cold cuts. Deli paper in hand, she grabbed the dressing she'd bought and closed the door with her hip, putting both on the kitchen counter before searching for her recently-purchased whole wheat bread.

The groceries were her contribution to the Castle household. Since returning to New York she only ventured home to pick up more clothes, for the closet space she now had in her fiance's bedroom. Unfortunately – in her opinion – "home" was still her old apartment. When she moved to DC, she kept her New York apartment for an extra month in case her new job didn't work out. She was very thankful that instincts made her hold on to it. Otherwise the move into Castle's loft would have been out of necessity, not romantic gesture it should be. Castle had dropped hints that he wanted Kate to live there permanently after things at the loft settled down, meaning, when he worked out his issues with Alexis and got rid of the boyfriend.

Kate and Castle realized quickly enough that both Pi and Alexis were using the missing passport as a paper-thin excuse. Maybe it was really missing, maybe it wasn't. The engaged couple couldn't be sure. However they did know that, after several attempts by Castle to educate Pi on protocol for replacing a lost passport, the teen didn't seem very concerned about traveling in the near future. Castle, Kate and even Martha were dismayed when Pi announced that he wanted to stay in New York both for Alexis and to continue his summer adventure abroad. That was when Castle finally snapped and said that he had to get a job to cover expenses for the length of his stay. The younger Castle gave her father a hostile glare for that, but Pi agreed that "Mr. C" had been generous enough and he should start earning some money for himself.

But he didn't offer to get his own place. He also refused to work for any of the many companies that would "compromise his morals," especially "evil corporate empires like Starbucks." Even Kate had been annoyed by the slam against her beloved coffee.

At the moment though, she would be much more annoyed if she didn't find the bread in the next five seconds. Where was it?! "Castle!" she called, knowing he would hear her from his office. He promised to take a break from writing and join her for lunch. "Where's the whole wheat bread?!"

"We don't have any!"

About to check the fridge again, Kate paused as Castle wandered in. "We don't have any?!" she asked in disbelief. "I just bought some two days ago!"

Castle grimaced, like she'd reminded him of an unpleasant experience. "Pi and Alexis purged the kitchen of gluten when I wasn't home. Dairy too."

"Gluten?!"

"Wheat. Includes bread, cookies. Cake. Basically everything good in this world, they threw away."

Shaking her head in denial, Kate checked more cabinets and the pantry to confirm his claim. "They just...tossed it in the garbage?! That's so wasteful! I remember he's fruitarian, but what could Pi have against...cookies...Oh my God."

She ran to the freezer and began tearing apart the contents, hunting for her last box of Thin Mints. It was the one remaining survivor from her Girl Scout cookie stockpile she'd accumulated earlier in the year, and...the green box was missing. She could clear out the entire freezer to check, but she could tell it wasn't there anymore.

First coffee...now this...

Her fists clenched and unclenched repeatedly as she stood in front of the cold air.

"Castle...if I see Pi's face anytime soon, I can't promise I won't rearrange it."

Laughing, Castle put a comforting arm around her with one hand while he closed the freezer door with the other. "While you know I'd love that, rearranging Pi's face isn't necessary. I have my own Girl Scout Cookie supplier and will get you all the Thin Mints you want."

"Thank you." She ran a hand through her hair as she raised an eyebrow at her fiance. "'Girl Scout cookie supplier'?"

"They exist. My own addiction goes back to when Alexis was a Daisy."

Shaking her head in amazement, Beckett picked up from where she'd left off."So, speaking of Alexis, let's go back to my questions. "

Castle's shoulders sagged dejectedly. "Well, we've both been thinking that Alexis brought Pi home to get even with me for proposing to you without talking to her first. This act of civil disobedience could be an extension of that. Again, she has every right to be upset, but our engagement happened very quickly. And I think Mother called her the second I left for the park with the ring in my hand."

"But what does have against gluten and dairy?"

Shrugging, he replied, "Something about GMOs and growth hormones..."

"The eggs are missing too and those are protein, not dairy." Perplexed by the mess of contradictory beliefs that was Alexis' boyfriend, Kate drummed her fingers on the counter as her detective brain tried to figure him out. She had yet to succeed in the weeks since she met him. Whenever she thought she had Pi's MO down, he revealed another layer of crazy.

...like disposing of her Girl Scout cookies. The jerk.

"I doubt his 'morals' are based on well-informed opinions," Castle pointed out. Instead of continuing their banter about the food protest, a rare somber expression came over his face. He seemed lost about the whole ordeal. "So...what do I do? About Alexis, I mean. We've never...we've never been like this before, Kate. We've always been so close but now I keep screwing up and she keeps not talking to me about it. Why did she bring Pi home instead of just telling me her feelings were hurt?"

Though Kate wanted to be angry at Alexis for the teen's immaturity, she couldn't, not when she herself experienced the same situation more than once. "It's not so easy," she murmured, her eyes lowered. "My father never dated a lot, but once in a while he would go out with a woman more than a few times. It was always...awkward, strained, to talk to him about them. Even if I got along with them. Not to 'take her side' or anything, but Alexis and I really haven't bonded much...she's probably closer to Lanie because of the internship. Maybe she still doesn't know me well enough to decide if I'll fit into your family. Springing our engagement on her made it worse. She's probably convinced herself that you don't care what she thinks anymore, at least about us."

Rubbing a hand over his face, Castle didn't answer right away. He was most likely processing what she'd told him and pairing it with Alexis' behavior since he started dating Kate. Soon after, guilt came over his expression. "I guess...this is no excuse, but I guess...with her at college...I forgot to be as careful as I would've been, if this happened when Alexis was younger. If Alexis was fifteen, sixteen...I would have run everything by her, checked constantly that she was okay. But now...to me she's always more of an adult than I am. That was our joke. Of course she's still my little girl, but also...a grown woman, who would speak up if something was bothering her. I just gave her too much space. Since she was living in a dorm, it never occurred to me that maybe she needed me more than I thought."

Her heart was so full of love and affection for her fiance that she had to hug him. Her arms around his neck, Kate kissed his cheek before lying her head on his shoulder. "No one's perfect, Rick. My dad tried too. Same as you, he would ask how I was, but usually gave me space until I worked through my feelings. I think...Alexis and I have that in common. We're both very private and have trouble admitting when we're confused or hurt."

The comparison made something click for Castle. His eyes widened as he stared down at the top of her head. "You should talk to her."

"Castle..." she began in a warning tone.

"I will too, don't worry," he assured her. "I'm not pawning this off on you. But I think maybe, after Alexis and I are back on the same page, you should tell her what you told me. Maybe while you're out spending the day with her?"

The idea wasn't a bad one. Several times over the past year she'd wanted to do just that, but she never had the opportunity. "I'd like that. Alexis and I are long overdue for a shopping day."

"I'll give Alexis my credit card," Castle joked. "You're free to use it too."

Kate shook her head. She could never spend someone else's money like that. "No thanks, I've got my own."

Kissing her hair, he whispered, "I love you."

"I love you too."

They went in for another kiss, but stopped when Martha stomped down the stairs, even more enraged than Kate had been earlier. "Where is that...that ne'er do well?! That ratty-haired rodent?!" she shouted, her hands on her hips as she surveyed the loft. "Where is he?!"

"Alexis took Pi sightseeing," Castle answered, unable to hold back a smile at the poetic insults. "Why is he a ratty-haired rodent, Mother? I agree, but I'm curious to know why."

"He used my hairbrush!" she shrieked. "My best brush...one that I won't be able to replace because God only knows where I got it twenty years ago, completely ruined." She held up the evidence – a wooden paddle brush that now had bent bristles and clumps of knotty dark hair. "I leave it in the bathroom once and that...that..."

"Weasel?" he prompted.

"Yes, that weasel destroys it!" she screeched, her other hand on her hip. "Richard, I have been as patient and welcoming as possible through all this, but you have got to do something."

Her son nodded. "Way ahead of you, Mother. Don't worry."

"Good." Her complaint submitted, Martha whirled around and went back up the stairs.

Castle and Kate burst into laughter, more at Pi's nervy antics than Martha's outrage. "He is so out of here," Kate predicted. "With Martha on our side, we can't lose. But most of all you need to repair your relationship with Alexis. If Pi ends up staying, okay, but...you have to find the root of the problem..."

Her fiance gave her a hopeful look. "Does it count if I know the square root of Pi?"

"No, Castle."

"That's 1.77, by the way..."

"Impressive. Still doesn't count."

The smell of more fruitarian crud...er, food, wafting upstairs from the kitchen, Rick went down the hallway towards his daughter's room. He wasn't thrilled about another inedible meal courtesy of Pi, but it did give him the opportunity to chat with Alexis while the boyfriend cooked.

Alexis didn't glance up from her laptop at her father's knock on the partially-open door. "Hey Dad, what's up?"

"Can I come in?"

"Uh...sure. I was just catching up with some of my college friends. It's better for Pi to have a lot of room when he's cooking anyway." She closed her computer and raised an eyebrow as he stepped in, shutting the door most of the way behind him. "Something wrong? Did he want my help?"

"Oh no, he's good. Last I checked the so-called 'eggplant 'steaks' were getting nice and crispy. I told him I liked mine medium rare."

Alexis sighed. "Dad, please have an open mind. Didn't you eat a whole bowl of 'cow's foot soup' once?" she pointed out.

Her father shrugged. "I was being polite. You can bet good money I wouldn't order it off a menu."

That got her to laugh. "Okay, fine, the 'fruitarian' thing is kind of weird. But it hasn't been every night. Most of the time he does only cook for himself. This is his way of thanking you and Gram for allowing him to stay here for so long." She turned her wide blue eyes on him and smiled sweetly, as if saying, Isn't my boyfriend sweet and not a mooch?

"Who paid for the groceries?" he retorted. So far he hadn't seen Pi buy anything himself. Alexis weakly insisted that he had his own savings, but even she knew no one believed her.

A frown quickly replaced her forced smile. "We've set up a system, okay? He'll have to go home soon since he can't find a decent job here, so I'm going to write down any money I loan him until then. He can transfer it all to me over the Internet..."

Rick winced, biting his tongue to keep from yelling. After about half a minute he thought he could trust himself to speak. "Alexis..." Nope, still anger there, all of it towards the delinquent currently messing up his kitchen. He let out a deep breath and started again. "Alexis...throwing out all our gluten and dairy, I can get past it...Beckett might not, but I can..."

Before he could yell at her for the incident, again, Alexis quickly defended herself and her boyfriend. "I apologized for that. So did Pi. We both realize we crossed a line, plus created a ton of garbage. One of the reasons he's making this dinner is to show how sorry he is, and if there's any way I can pay for a new box of Thin Mints..."

"Oh, there is," Rick assured her. He wasn't going to let her off the hook for that one. "But my main concern is Pi. Are you absolutely confident that you're going to get this money back?!"

Not answering immediately, Alexis seemed to be deciding if it honesty would be the better option. Apparently her decision was in his favor. "No, but I really like Pi, okay Dad? If he doesn't stay with me then we'll never see each other again. It's like..."

"Don't say me and Beckett," Rick warned her. "Beckett and I are an older, more experienced couple who love each other and earn our own livings. If you're mad at me for proposing to her, just let it out. Don't use it as a reason to waste my money on Pi...or a distraction so you can get back at me without revealing how you really feel. The bottom line here is...is he worth it?"

His speech had affected her. She wasn't so brazen anymore, her voice quieter. "Worth what? Are you going to punish me like a little kid if I don't break up with him? I'm eighteen, Dad. You can't..."

This was the argument he'd prepared for. "You're eighteen, but you're also living under my roof and using my money," he challenged. "Sure, you can declare your love for Pi. But that means I'm cutting off your debit account so you can't support him. How much longer do you think he would hang around if you couldn't buy him organic eggplant or whatever else he needs for that unique diet of his?"

Maybe he was being harsh, but it was working on her nerves like he wanted it to do. The signs were subtle but he could detect the fury in her expression, and the way clutched her laptop tightly to her body, her knuckles devoid of any color. Finally, for one of the few times in her life, she gave up her pretense of self-control.

"You didn't even tell me!" she yelled, loud enough that others in the household probably overheard. Tears formed in her eyes and started rolling down her cheeks. "I wasn't happy that you were dating her but you didn't care! You proposed to her anyway! Without asking me how I was, if I was ready for it! Is she worth it, Dad? Is she worth ignoring everyone else in your life? For years now you've been putting yourself in danger when you're not even a cop and...you don't care that Gram and I worry! That we worry every single day and if you marry Kate...it's never going to stop! Not just the danger on the field , but everything she puts you through, how there's all this drama and history and...when does it end, Dad? When she leaves us like Mom and Gina did?!"

Alexis finally broke down, computer sliding out of her lap as she shifted over to the mound of pillows at the head of her bed. "Go away," she pleaded, her voice muffled. "I'm sorry about Pi, I know you're going to marry Kate anyway, so please just go."

Though tempted to do that so he could process his daughter's outburst, Rick didn't move from the edge of her bed. He couldn't walk out after that or she'd think she'd been right. But what am I going to say?! he thought helplessly. How do I justify the risks I've taken these past five years?

Well, maybe he didn't know what to say. But he couldn't let her cry alone.

"Come here, pumpkin," he said softly. She didn't protest when he pulled her into his arms. "Look, I...okay, I can't promise that Kate and I won't end up divorced. However, that doesn't mean I should just give up and never get married again, right? If you're really, truly in love with someone, then...it's always worth it." He grinned when she gave him a small smile. "Sweetheart, I can promise you that Kate and I...I know in my heart that we're different. For her, I'm her 'one and done.' I intend to make the same effort."

The tears drying out, Alexis wiped her eyes as she pulled herself up, leaning into his arm with her hands in her lap. "If that's true, then...are you still going to help at the precinct after you're married?" she whispered. "Are you going to write Nikki Heat books forever?"

Her question made him think. He was too busy staying in the present to consider the distant future. "Honestly? It's impossible to guess," he confessed with a laugh. "My calendar only goes until next year. I don't have a 'forever' plan yet." At her sigh, he added, "But I do know that me working with the police is hard on you and Gram. I don't acknowledge that as often as I should, and I'm sorry for that. The way I see it...by doing this, I'm helping a lot of people. To me...that's also worth it. You have to admit that your dad saving the city was very cool. And I'm pretty sure Beckett and I actually saved the world once."

"The world, Dad?"

"It's true! Your dad's a superhero!"

Alexis couldn't hold back her laughter. "Maybe he is," she said, acceptance in her eyes. She then broke eye contact, embarrassment flooding her face. "And I think, maybe...bringing Pi home wasn't the smartest idea I've ever had." Still feeling slightly insecure, she raised an eyebrow at him. "Did you come in here just so you could convince me to break up with Pi?"

"Can't deny that one. Pi has to go."

Since she realized how silly the question was, Alexis laughed with him. "Okay, Dad. I'll have a long talk with Pi after dinner."

"How about before dinner?" he suggested mischievously. "It'll give us time to dump the 'steaks' and order us some real food."

How could I be so petty?! The cookies were in my hand, I knew they were Kate's, but I threw them out for one moment of childish revenge. Stupid, stupid, stupid...

The chant played on repeat in Alexis' head as she rode in the cab with Kate, shopping bags covering the floor around their feet. Her father's fiancee was gushing about the shopping day they'd just spent together. Guilt, already there because of the Pi ordeal, multiplied in Alexis' stomach until she felt sick. Now she wouldn't even be able to enjoy their afternoon snack. At the moment they were driving towards a bakery uptown she thought Kate would love – another way for Alexis to to make up for what she did, besides the apologies she'd already given.

"That dress was made for you, Alexis," Kate went on, nudging the appropriate bag with her high-heeled foot. "The casual sweater one? It'll be comfy to wear around campus, and keep you warm in the early winter months..."

"Mhm..." Alexis wasn't acting distant towards Kate on purpose. She'd actually had a blast with her soon-to-be stepmother. Even though Pi left only a few days ago, the heartbreak – if there'd been any – had diminished to almost nothing. Maybe it mirrored her bond with Pi, if she'd ever had one. Truthfully the biggest reason she brought him home was to prevent Kate from moving in (and of course to annoy her father). Now that she wasn't so bitter, any 'love' she had for the radical hippie instantly began to fade. Though she'd kissed him good-bye at the airport and told him to write, if she were to be brutally honest...she wouldn't mind if she never heard from him again. Her family was wrong in that he wasn't a bad person. He just didn't fit with her personality. She wanted someone who matched her intellect, her ambition...not only her ideals.

And now that she wanted to start over with her dad and his fiancee, she absolutely hated herself for how she behaved. She was surprised Kate treated her with as much friendliness and warmth as she did. Then again, the woman squared off with murderers for a living. Scheming teenagers wouldn't be very intimidating to her.

Finally Kate noticed Alexis' unease. "You okay, sweetie?"

In Alexis' frazzled state, that was all it took. "I'm sorry!" she blurted, startling the cab driver. He wisely continued ignoring them. "I'm sorry about the cookies, and the other groceries you bought for us. Pi didn't throw them out. I did. It wasn't for the environment either. I was really mad at you and dad...and so, so stupid..."

Alexis was shocked when Kate wrapped her in a comforting hug. After they broke apart, Kate gave her a knowing smirk. "That's nothing. At least you only threw out groceries."

"But..."

"I was a few years older than you..." Kate continued, waving away Alexis' apology. "My dad started to get serious about someone. She came over for dinner...and I wrecked her car."

Alexis couldn't hold in her laughter. "How?!"

"Well hers was very high-end, and Dad warned me about playing nice so I complimented it. She wanted brownie points too so she offered me the keys." Kate made an innocent face at the amused teen. "Then after, I squeezed into a parking space that turned out to be much tighter than I thought."

Amazed to hear a wild story like this from the homicide detective, Alexis wanted every single detail. "What happened?"

Though her face became slightly red with embarrassment, Alexis could tell that Kate still didn't regret the incident. "There was a metal barrier behind me in the street. It somehow wound up attached to the car's bumper." She shrugged, her eyes sparkling. "In my defense I was only going thirty, the legal speed limit, on impact."

"But you were parking. You shouldn't have been going anywhere near that fast...right?"

The detective's grin widened. "That's the trouble with high-end cars, especially new ones...the gas pedal can be a little too sensitive. Whoops."

"Oh my God..."

The two women shared another round of chuckles, the knot in Alexis' stomach slowly dissolving. She completely forgot that her dad's fiancee would have also dealt with potential stepmothers. Their day of bonding, and Kate forgiving her so easily, made Alexis wonder if they really could become...not mother and daughter, but friends. "Thanks, Kate," she said, offering one of the first genuine smiles she'd given all day. "I do feel bad that we don't hang out more often, but honestly...I've been afraid to get close to you. I'm so afraid you and Dad will have a fight and I'll never see you again. No one's become part of our family and stayed before."

"Oh, honey..." Kate looked teary-eyed as she wrapped Alexis in another hug. Becoming serious, almost stern, she then made direct eye contact and kept a hand on Alexis' shoulder. "I plan on marrying your father. I really do. Every day, every time I see him, I see myself walking down an aisle and he's at the other end. I don't know where that aisle is, or what dress I'll be wearing, but I am going to marry him. And I do not plan on leaving him after that."

Swallowing the lump in her throat, Alexis nodded and let her father's fiancee continue.

"That said..." Kate added with a sigh. "I know that my word won't be good enough to convince you until I prove myself, right? So, since you are having these doubts, let me just play devil's advocate for a moment. If...and that is a very unlikely, 'never going to happen' kind of if...your father and I do part ways because of something we can't control...I swear, I will be in your life as long as you'll have me. You are free to call me with any problem, or if you just want to vent, or anything. I hope that's the relationship we'll have in the future when I do marry your father. I realize that you've been fine without a mother so far and you don't need one now, so think of me...as a friend, a supporter, someone to go to for advice, a pep talk, or if you just want to vent. Is this all okay with you?"

"Very okay." Alexis hugged Kate again, thrilled to finally have the reassurances she'd been longing for. However Kate was right about one thing – they were just reassurances, comforting but not an indication of how this would really work. They would have to build their friendship slowly and see where it went.

Wanting one more reassurance before they let the subject drop, Alexis glanced up at her future stepmother. "Just...please, don't break his heart again."

Speechless, Kate could only nod in understanding. There was no reason to say anything, or to make another promise. The most they could do was hope that their intentions were enough to keep the new family together.

Sitting back in their seats, the tension between faded as both women now felt more relaxed around each other. Kate glanced at her future stepdaughter. "We're good, right? Because I was thinking we could make this a monthly thing, though maybe we can pick other stuff to do sometimes. For one, my poor credit card wouldn't be able to handle it."

Alexis laughed. She'd used her debit card for the clothes she'd bought, aside from the one or two items Kate insisted on picking up in order to convince Alexis to bring them home. As for her own shopping though, Kate kept her card in her wallet most of the time, only relenting for dress shirts or slacks she could wear at the precinct...though the detective had been very tempted by a pair of three-inch stilettos. "Noted," the teen replied. "I'll look into events around the city."

Less than ten minutes later the cab finally pulled up to their destination, which had been a mystery to Kate since Alexis mentioned it that morning. The only details the teen gave was that it involved snacks, and that they would have to get there early enough so they didn't ruin their dinner. Their arrival time of a quarter to four qualified since they probably wouldn't have dinner until eight or later. Alexis paid the cab driver, over Kate's protests, then both carried the bags out of the cab and started down the block.

When Alexis slowed down as they neared the bakery store front, Kate paused to check out the bright and colorful awning. Bold Imitations was written in script across the front. "Oh, I've heard about this place!" she exclaimed, delighted by the surprise. "Lanie said they make their own versions of famous snack cakes...yeah, they should have Twinkies, Sno Balls, Yodels..."

She trailed off as Alexis pushed open the door and they stepped inside, which led them to face a long display case along the back wall. Kate's eye immediately went to a section near the cash register in the center. "...and Girl Scout cookies," she finished, almost tearing up at her future stepdaughters' thoughtfulness. "Alexis, this is so sweet!" She then rolled her eyes at her unintentional joke. "Oh God, I made a pun without even thinking about it."

"Dad would be proud," Alexis teased. She couldn't stop smiling at the detective's reaction. Because of her guilt for both the cookie incident, Pi, and her attitude towards the engagement in general, she came up with this field trip to show Kate that her numerous apologies really were sincere. The delectable-looking upscale cookies, which were the size of cupcakes, confirmed her choice of bakery. They vaguely resembled their brand-name counterparts but had been super-sized and infused with fresh, quality ingredients. "I'm glad you like it. Dad said I had to replace your Thin Mints. I would have done it anyway, and while this isn't a green box you can keep in the freezer..."

"It's better. Much better. Thank you, Alexis."

"Actually, it's my way of saying thank you for today," Alexis replied. Relieved that her apology had been a success, Alexis watched Kate run up to the glass case, critically analyzing all of the cookies to decide which to order first. Alexis approached the cash register and solved the dilemma. "Hi," she said to the cashier as she indicated the cookie display. "We'll take one of each."

A/N: Unfortunately Bold Imitations isn't a real bakery...as far as I know!