When you know the notes to sing
You can sing most anything.
-Oscar Hammerstein II

Beckett's stomach churned as she went back out onto the stage for the chorus rehearsal. The conversation with Castle had left her with a whirling collection of emotions that she just couldn't deal with right now.

Standing at the piano, she arranged her score book on the music stand and flipped the pages, watching from the corner of her eye as Castle greeted the singers and made his way as casually as he could manage to the front-row seats where the group of older sopranos always sat.

Her decision to open up to Castle about her mother's suicide had surprised her as much as it had him; it certainly wasn't something she had thought about in advance, but it had felt right, in the moment.

During the orchestra rehearsal earlier today, when they had run through the soprano solos, Kate had experienced a sudden moment of clarity, realizing with her conscious mind what her hindbrain had already decided: that she was going to sing the solos. Somehow, over the past day, ever since Castle had first put the idea into her mind, her subconscious had chewed it over and come to a decision, even while consciously she had still been denying it, resisting it.

But it made sense that it would be during the rehearsal - when, as Castle had noticed, she had been silently mouthing the soprano solo part while playing the music - that her subconscious chose to make its decision known. In that moment she had realized the same things Castle had just said to her in the library: that she loved singing, and that she loved these particular pieces especially, and that she couldn't let the Messiah concert go on without them.

And, perhaps, that after ten years it might finally be time to start healing these lingering emotional wounds; to open herself back up to the possibility of a career as a singer; to absolve herself of needless guilt; to forgive her mother. To move on.

All of these things had been swirling through her mind since the orchestra rehearsal ended, and had come to a head when Castle sat down for lunch with her. She needed Castle to know; if she was going to attempt the solos, she needed him to be in the right frame of mind, to refrain from making light of it. She needed him to understand what it would cost her.

She had only known him a few days, but she had already seen glimpses of the more serious, sensitive side of him underneath the cocky clowning exterior. So she thought - she hoped - that he would be able to understand everything she was trying to tell him.

Mulling over all of this, she somehow managed to greet the chorus members who passed by the piano on the way to their seats, and to answer the questions that came her way; she caught sight of Jason standing among the tenors, resolutely not meeting her eye, and Lanie among the altos, being chattered at by her neighbors, giving Kate a smile and wave. She smiled back, and turned to check on Castle again. He was still deep in conversation with the sopranos, and it was time for the rehearsal to begin. Kate wondered whether it would be appropriate for her to start the warm-ups while Castle was still chatting.

But just as that thought went through her mind, Castle broke away, disentangling himself from the conversation with the white-haired women. He came back across the stage to where Beckett was standing by the piano.

"They identified the one who kept losing roles to Annabel," he told her under his breath; "her name is Sara, third row, on the right, in the yellow shirt. And they said that she left Tuesday's rehearsal early."

"We should get started" was all Beckett said, but her eyes were seeking out the yellow shirt, and making note of Sara, studying her. Wondering: was this the face of a murderer? Was a lost job opportunity, or even a series of them, really a strong enough motive to drive someone to kill? She supposed that someone like Detective Gates had probably seen it all, the reasons for murder both profound and banal. But to Kate Beckett, it was all still strange and mystifying.

Castle had found it easy to worm his way into the good graces of the older sopranos, who seemed delighted that he had come to talk to them. The two he had in mind had been bickering when he got there, and were only too happy to refocus their attention on him.

He had their types pegged already: Doris, the one with the short white hair, was a complainer, never fully satisfied, always able to find something to grouse about; while Judith, the tall one with white hair in a long braid all the way down her back, was the more helpful and accommodating type, but with a steely core.

"It's been a wonderful week working with you ladies," he began, flashing a charming smile that got them both smiling back. "I hope you're enjoying it as well."

"Yes, it's been great," Judith smiled back. "And you're a lot easier on the eyes than Perlmutter, Maestro," she added, nudging him with her elbow.

"It's just too bad we aren't doing Behold The Lamb," fussed Doris, peering earnestly up at him. "That one is so lovely, isn't it? When we do Messiah with my church choir-"

"Shut up, Doris. Maestro Castle doesn't care about your church choir," Judith interrupted sharply, and Castle's eyebrows rose in amusement. Doris didn't seem fazed at all.

"Well, anyway, we're delighted to have you, Maestro," she said. "The concerts are going to be lovely. Such a shame about Annabel, though. She was a dear."

"Oh yes, very sweet," Judith agreed. "Her best friend's brother was in my second-grade class back when I used to teach."

"You know," said Castle, quickly seizing the conversational opening, "speaking of Annabel, I heard that she had been getting a lot of roles recently that other sopranos in this chorus had auditioned for."

"Ah," said Doris knowingly. "You must mean Megan."

"Are you toking again?" Judith demanded of her friend. "Megan hasn't auditioned for a thing since she got pregnant." Both women turned to smile in the direction of a soprano in the second row, whose hands were resting lightly on her rounded belly. "It's Sara you want, Maestro," Judith added, jerking her head significantly back to the left. "Up there in the third row."

"Oh, yes, of course, Sara," Doris agreed. "She's been auditioning like crazy lately."

"Never gonna happen," Judith said critically. "She's just not that good, but, you know, hope springs eternal. Speaking of which," she went on with a sly look, "how are things between you and Kate, Maestro?"

"Um, I'm not sure what you mean," he lied, and hastily changed the subject, "but are you sure that Sara had auditioned for parts that Annabel ended up getting recently?"

"Certainly, several of them," Doris nodded, "oh, and Maestro, if you're going to talk to her about that, would you say something to her about leaving rehearsals early? I don't like to make a fuss, but it's so disrespectful. She left early on Tuesday, as a matter of fact."

Castle's interest was piqued, but he kept his cool. "You don't say?" he asked mildly. "She left our rehearsal early on Tuesday?"

"Only about fifteen minutes early," Judith said, "but people do notice these things, you know, especially if you're all the way in the middle of the row."

"Right, of course." Castle tilted his head, digesting this. "Well, I'll certainly keep it in mind. Thank you both, ladies. It's been such a pleasure chatting with you."

He moved to depart, but Judith's hand closed firmly around his forearm, stopping him. He turned back to her again, raising his eyebrows questioningly.

"Maestro," the white-haired woman said, and he quailed at her stern tone, which she had undoubtedly perfected over her many years of teaching the second grade. "You seem like a nice young man, and goodness knows our Kate could use some fun in her life. But just keep in mind: if you break her heart, we will make you suffer."

"Severely," added Doris, nodding, with a gentle smile.

Castle opened his mouth, then closed it, completely at a loss for words. All he could do was nod and walk away.

Beckett kept an eye on Castle as he moved to take his position behind his music stand, the chorus quieting as they saw him preparing to begin. Kate thought that he seemed slightly rattled from his conversation with the sopranos - more so than would be explained by learning that their suspect had left the stage early on the day Annabel was killed - but then again, she told herself, maybe she was just imagining things. Maybe it was as hard for Castle as it was for her to envision someone like Sara committing murder.

"Okay, everyone," Castle said, "let's get warmed up." He nodded to Kate, and she began leading the chorus through some light stretches and then a series of breathing and singing exercises.

When they were done warming up, Castle gave the chorus a version of the same little speech he had given the orchestra earlier, acknowledging Annabel's death and refocusing the group on the task at hand. Then he said, "I'd like to start at the end today, and work our way backwards. Can everyone turn to the Amen section, please?"

The Amen at the very end of Messiah was long and complex, and Kate admired Castle's strategy, leading off with that movement at the beginning of the rehearsal while the chorus members were still fresh. Castle stopped them repeatedly as they worked through the movement, and no one complained; the difficult spots needed to be addressed. By the time they went back to the beginning of Worthy is the Lamb and ran through that movement and the Amen without stopping, all of the singers were nodding their heads in satisfaction, pleased with the progress they had made.

Kate caught Lanie giving her a look that seemed to say maybe he does know what he's doing after all, to which she responded with a small smile and an even smaller nod.

The next chorus, in reverse order, was Hallelujah, which Castle decided to skip; a few chorus members groaned disappointment, but it made sense. Most of the singers had sung that particular piece dozens of times and could probably perform it in their sleep.

So they did Lift Up Your Heads, and then His Yoke Is Easy, and then it was time to break.

"Fifteen minutes, everyone," Castle said, and made a beeline for the bass section as the chorus members began to disperse off the risers.

Kate hastened to catch up with him, grabbing his elbow. "Castle, watch your step."

"I know how to navigate stairs, Beckett," he replied with a small mischievous smile. She narrowed her eyes at him.

"That's not what I meant and you know it," she hissed.

"Don't worry about me and Daniel," Castle said confidently. "You take point on the soprano, Sara. Find out her alibi, if she has one." Catching her glare, realizing his error in trying to give her orders, he added hastily, "Please? Um. I meant to say, hey Beckett, if you wouldn't mind-"

"Okay, okay," she sighed, rolling her eyes. "But only because if I don't do it, you'll bother her yourself."

He just grinned. "We make a great team, don't we?"

"Shut up."

So Beckett made her way between the gathered singers until she found Sara, who was eating an apple and chatting with a few others. "Can I talk to you for a moment?" Beckett said quietly, and Sara detached herself from her friends to step aside with Kate.

"Sara, I heard that you slipped out early on Tuesday," Kate began, and saw the other woman's eyes widen.

"Yeah, I did," she confirmed, a little nervously. "Um, is that a problem?"

Kate realized belatedly that she had made it sound like she was about to scold Sara for cutting out on the rehearsal. But some instinct told her that immediately reassuring Sara wouldn't be the right move, so instead she pressed on it.

"Do you want to tell me where you went?" she asked, folding her arms over her chest very deliberately.

"Of course," Sara said quickly, her apprehension growing. "I'm really sorry. Really sorry. But I had gotten an audition and it was the only time they could hear me. Do you know Mario Ribeiro? He's this amazing director," she babbled anxiously, "and he's doing this off-Broadway production of Into The Woods, and I'm really hoping to be Cinderella."

"I see," said Kate, keeping her expression neutral. She was remembering a common interrogation technique that she had learned about during her detective obsession phase in her teens: the trick of creating a silence in a conversation, to encourage the other person to fill it.

"Have they found someone to do the soprano solos for this concert?" Sara asked, still looking very nervous, searching Kate's face for her reaction. "It's so awful about Annabel, isn't it?"

"Terrible," Kate agreed, and waited again.

It worked. "I would have loved to be considered for it myself," Sara rattled on, "but actually I won't be able to come to the last concert on Sunday. My brother's getting married that day." Still getting no reaction from Kate, she spoke faster, anxious. "I asked Perlmutter about it way back in the spring and he said it was fine if I skipped that one concert, since I'm just in the chorus. But obviously I couldn't do the solos, so I didn't even consider it. Is that okay?"

"It's fine," Kate said, relenting. "Don't worry about it, Sara. Just, if you're going to miss a rehearsal or performance in the future, please make sure to tell me ahead of time."

"Oh, I will. I will, I promise," Sara gasped, relieved. "Thanks, Kate."

"Good luck with that audition," Kate added, distractedly, turning away.

She knew that a good detective never ruled out a suspect based on that person's word alone, but she found Sara's excuses fairly convincing. Kate made a mental note to pass along this information to Detective Gates; the police could probably contact the director to confirm that Sara had been auditioning at the time of Annabel's death.

In her mind, Kate envisioned Castle's diagram of the murder investigation, with Brett's name crossed off. Now she mentally drew an X through the "jealous soprano" box as well, leaving them again with just one suspect: Howard Grainger. But could Howard really have done it, she wondered for the umpteenth time - killed a soloist over a contract dispute?

"Get anything?" asked Castle's voice from directly behind her, and she jumped, startled.

"Don't sneak up on me like that!" she snapped.

"Sorry," he shrugged, looking anything but. "You were deep in thought there, Beckett. Is Sara our killer? She looks so simple and innocent, which of course makes her a great suspect."

"No, I hate to burst your bubble, but I don't think she is." Kate told him about the audition, and he frowned, rubbing his chin.

"That shouldn't be too hard to verify," he mused. "I've heard of this director, Ribeiro. I know a guy - I could give him a call."

"And say what? That you're investigating a singer for playing hooky from the last fifteen minutes of a rehearsal?" Beckett shook her head at him. "Castle, it's none of your business to make that call. Let the police do it."

"But what if the director gets spooked by having the police call about Sara, and it loses her the part?" he pointed out, putting on his innocent face. "Would you want to be responsible for that, Beckett?"

"Oh God," she sighed, rolling her eyes, "just tell me what Daniel said about Annabel's contract."

"He wouldn't say anything," Castle complained, frowning again. "Invoked attorney-client privilege, and when I said that I think that stops being applicable after the client dies, he asked me what law school I went to."

Beckett couldn't hold back a snort. "Well, you deserved that."

"Maybe, but the suspense is killing me, Beckett." He followed her back onto the stage, lowering his voice. "Isn't it driving you crazy not having this one crucial piece of information, about Annabel and Howard and the contract dispute? What are we going to do?"

"We're going to finish rehearsing," she replied firmly, and gave him a tight-lipped glare when he opened his mouth to object. It worked; he snapped his mouth shut again, though he was still scowling.

The rehearsal resumed, with Glory to God and then For Unto Us. Beckett noticed Daniel giving Castle a baleful glare from the middle of the bass section; she wondered what Castle had said.

After they had finished running through all of the choruses in reverse order, Castle again asked the singers to call out the spots they wanted to work on, and he managed to get through all of them before the time was up.

"Great work, everyone, really great," Castle said enthusiastically as the chorus members closed their scores. "I'm feeling good about these concerts and I hope you are too. I'll see you all back here tomorrow for the dress rehearsal."

Castle was grateful that there weren't as many people as usual coming to him and Beckett with miscellaneous questions after the rehearsal was over. He needed to talk to her, badly.

Only a few minutes after he called the rehearsal to an end, the hall had mostly cleared out, with just a few chorus members left gathering up their belongings. Castle was alone on the stage with Beckett as she made some final notes in her score.

"Listen," he began without preamble, "I'm sorry for what I said earlier, about your mom. I was out of line."

Beckett's hands stilled. She looked at him, guarded.

"I shouldn't have said she was weak," he went on. "I, it was, that was wrong of me. I apologize."

It had been bothering him throughout the rehearsal. He was no expert on suicide, but he knew that it was never simple; he had said as much to Alexis the other night. He didn't want Kate to think he was minimizing her mother's struggle by dismissing her as weak or selfish. In the moment, he had reacted strongly to Kate's pain, but in retrospect he regretted having passed judgment on Johanna's.

He held Kate's gaze and hoped that all of this came through in his eyes.

She drew in a slow breath and said quietly, "It's okay."

Castle felt his shoulders slump in relief and realized that he had been honestly worried about how she would react. What was this woman doing to him?

He opened his mouth, undoubtedly to say something else stupid and damaging, but before he could get a word out, he noticed two fiery-bright heads coming down the aisle of the performance hall.

"Dad!" one of them was calling, waving a pale hand, and he realized it was his mother and daughter.

"Alexis? What are you doing here?" He went over to the edge of the stage, looking down at his redheads.

"We came to get you for dinner," his daughter replied, coming up the stairs onto the stage and hugging him. "Wow, this is a beautiful hall. Have we been here?"

"Dido and Aeneas a few years ago," Martha said, ascending the stage as well. "Darling, aren't you going to introduce us?" she added with a nudge as she accepted Castle's kiss on her cheek.

"Mrs. Rodgers, it's an honor to meet you," Beckett said sincerely, coming forward with her hand out. "I'm Kate Beckett."

"Ahh, Ms. Beckett." Martha flashed a knowing look from Beckett to Castle and back as she took Kate's hand. "So lovely to meet you at last. We've heard so much about you."

"Oh, really?" Beckett said, pursing her lips, narrowing her eyes at Castle.

"And this is my daughter, Alexis," he said quickly, thrusting the teen in front of him like a shield. "Alexis, Kate."

"Nice to meet you," Alexis said politely, shaking Kate's hand. "I hope my dad has been behaving himself this week." She cast a glance over her shoulder at him. "Sometimes it helps if you just smack him."

"I've noticed that," Beckett replied, a real smile breaking loose now. "But no, he has been pretty good, mostly."

"Mostly!" he exclaimed in outrage, but wilted immediately under the combined force of Alexis's and Beckett's glares.

"Anyway, Richard, we thought you'd be hungry," Martha cut in, "so we came to fetch you, and we've a reservation at Antonio's..." She glanced at her watch. "...now-ish. Are you ready, darling?"

"Oh, um, yes," he said, a little awkwardly, wishing he had had just one more minute alone with Beckett to make sure things were okay between them. "Uh, let me just get my briefcase."

"You should join us, Ms. Beckett," Alexis said earnestly. "I'm sure you need to eat too, and we'd love to chat with you."

Castle's eyebrows went up, but he managed to keep his mouth shut and wait for Beckett's response. When he saw her smile back at Alexis, he was filled with an overwhelming surge of gratitude toward the universe for giving him this perfect, wonderful child. He knew Beckett would never have accepted a dinner invitation that had come from him, but who could say no to Alexis?

"Thank you, that sounds nice," Beckett said, and his heart soared.

A/N: Thank you to all reviewers, and in particular to those who expressed concern about Castle's apparent insensitivity regarding Johanna's suicide in the previous chapter. I hope this chapter has made things more clear as to my intentions with that scene.

I have sat next to the real-life Judith and Doris (not their real names) in community choir for nearly 15 years now. They always keep things interesting and I couldn't resist putting them in here. I hope you enjoyed them. :)

As always, please feel free to let me know what you think!