The next day Beckett was back at the precinct, staring at the murder board, but her thoughts were far away. Specifically, of course, her thoughts were on Castle and the not-really-a-fight last night. He hadn't called her that morning to beg her to bring him to the precinct, and she was wondering whether she should call him, or go over there, or...?

Her dilemma was resolved, or so it seemed, by the appearance of Martha, who showed up at the precinct just before lunchtime, looking unusually subdued.

"Martha?" Beckett said in surprise. "Is something wrong? You didn't leave Rick alone, did you?"

"No, no, of course not," his mother denied. "Alexis's afternoon class was canceled, so she came over to help Richard practice with his crutches." She paused, and asked in a lower voice, "Can we talk in private, Katherine?"

They sat side by side on the sofa in the lounge, where Martha leaned forward to put her hand on Beckett's knee, and sighed. "Darling, I don't know what happened between the two of you yesterday, but, well, Richard asked me to tell you not to come over tonight."

Beckett's gut clenched with dismay. "Oh," she managed, shocked. Was this it, then - the end of them? But they were just getting started. She hadn't even told him that she loved him yet. Her whole body felt frozen. She had to blink, hard.

"Oh, my dear." Martha shifted closer to her on the sofa, putting an arm around her shoulders. "Please, don't start imagining the worst. This is just a bump in the road. He loves you, darling, so much."

Beckett relaxed, just a fraction. "I love him too," she whispered. "I just - I just wish I knew what's bothering him. He wouldn't tell me."

"No. I couldn't get a word out of him either," Martha agreed. "He's a terrible patient, isn't he?"

Beckett tried to laugh, but it wouldn't come. "I guess..." she said painfully, "I guess this is part of why I dropped out of sight, after I was shot. So that none of you would ... see me like that."

"Ah." Martha regarded her shrewdly. "You hid yourself away during your recovery out of fear, Katherine. Fear of being vulnerable, being seen to be vulnerable. Fear of Richard's feelings for you."

"I..." She wondered if she were really that transparent. But she also could see where Martha was going with this. "I think I get what you're saying. What is he afraid of, then?"

Martha lifted her free hand in a gesture of helplessness. "If I knew, dear, I would certainly tell you."

"You know," Beckett said slowly, "all this ... our fight yesterday ... it all started when I asked him what he wants to do for his birthday." She paused, looked at the older woman. "Do you think that's it? He's upset about having to cancel our trip?"

Martha pursed her lips. "It's possible. He certainly has been looking forward to the tropical getaway with you."

"Martha," Beckett said determinedly, turning to face the other woman more fully, "I want to do something special for his birthday, to make it up to him. Something big." And in a flash she knew what it was. She remembered him a few weeks ago, during the reality TV murder case: Is this your Valentine's Day gift to me? A complex mystery where nothing makes sense? You know me so well!

"I want to stage a murder," she exclaimed, the insight popping out of her mouth as quickly as it had popped into her brain. "We'll arrange it so that he thinks he's witnessed a murder, and he'll try to solve it from the apartment. Like a modern-day Rear Window." She grabbed Martha's hand again. "Will you help me?"

Martha's face split into a wide smile. "What a fabulous idea, darling. Of course I'll help. We can use some of my acting students as the characters, and you and I can work out the script together. He'll love it."

"I hope so."

At the end of her shift, Beckett reluctantly went home to her own apartment instead of back to Castle's loft. She still didn't understand why he didn't want to see her, but she wasn't about to push. It would probably be easier for him to rest and recuperate without her around, anyway.

But she missed him. Her bed felt cold and empty. Despite Martha's reassurances - despite telling herself again and again that people often behaved irrationally and incomprehensibly when injured - she couldn't shake the fear that something had really gone wrong between them. Her stomach was queasy, and her head ached from trying to figure it out.

The next day, Beckett and her team solved the murder case they had been working on. After finishing the paperwork and eating a hasty lunch, she called Martha.

"Do you think it would be okay if I came over?" she asked hesitantly.

"Oh, darling. Please do." She could hear the smile in Martha's voice. "He'd kill me if he knew I was telling you this, but he's spent half the morning asking whether you've called, or whether I think he should call you."

"Oh," Beckett got out, briefly dizzy from the surge of relief that flooded her body. "Oh, uh, good."

"Do you want me to put him on the line?"

"No," she said hastily, "no, I'll just ... be there in a few minutes."

After she hung up, it only took a glance at Ryan and Esposito; they gave her a matched pair of nods, indicating that they would cover for her with Gates if needed. She grabbed her purse and coat, and took off.

Martha let her into the loft with a somewhat forced smile. "Terrible patient," she murmured, low, and then raised her voice to call, "Oh, Richard, look, Katherine's here."

Castle appeared in the doorway from his study, awkwardly steering the wheelchair, his expression hopeful and anxious and maybe a little embarrassed. "Beckett?"

"I'll leave you two alone," Martha said ungracefully, and exited hastily.

"Hey, Castle," Beckett said tentatively, walking toward him. He sat in place, his leg sticking straight out, watching her approach.

"I'm sorry," he said when she drew within arm's length.

"No," she started to say, but she couldn't help herself, and leaned down to kiss him instead. The flutters of nervousness in her belly melted away when he stretched up eagerly toward her, his hand lifting to cup her cheek, his mouth soft and sweet under hers.

"I missed you yesterday," he said against her lips. "I was so stupid, sending my mother to - I'm really sorry."

"It's okay," she promised, feeling as if her heart had just now started beating again. "I know it sucks, being stuck here like this."

"I'm getting better with the crutches, though," he said, his face lighting up like a little boy's. "Watch this." And he reached for his crutches and showed her how he could lever himself up out of the wheelchair and onto the couch. She resisted the urge to help, with some difficulty.

She wanted so badly to ask what had gone wrong the other night, why he had gotten so upset. But the words wouldn't come. He clearly wanted to pretend it hadn't happened, to go back to their familiar easy rhythm, and it was too tempting to resist going along with it. Later, she told herself; she would find the right moment and the right words to bring it up, later.

When he was seated on the couch, he reached out a hand to her, and she took it, coming to sit next to him. "See, I'm almost ready to come back to the precinct," he said hopefully, and she just smiled, kissing him softly.

"You'll be good as new before you know it," she hedged, and then, to distract him, she told him all about the case they had just closed. He listened eagerly, and asked questions, and gave a little satisfied sigh when she had finished.

"I wish I could have seen that guy's face when you arrested him," he said a little wistfully, and then, "I really missed you yesterday."

"I missed you too," she sighed, leaning into him. They kissed for a few minutes, slow and tender.

But soon Castle grew passionate again. "Kate," he breathed, pulling her even tighter against his side, his hands roaming her body. She sighed and kissed him again, lightly.

"Castle, you still can't-"

"I know, I know," he interrupted quickly, "but - just let me..." His hand slipped inside the waistband of her pants. She gasped a little when his thick fingers brushed over her damp flesh, but she twisted away, trying to stop him.

"I can't stay very long," she managed. "I'll have to get back to the precinct soon. Don't you want to-"

"This is all I want," he told her hoarsely, flicking the button of her pants open to give his hand more room. His other hand was pulling her shirt up and he bent down, awkwardly, trying to get his mouth to her breasts. But the leg brace constrained him and he couldn't quite twist far enough.

"Kate," he said wetly against her collarbone, licking and then biting down hard enough that she gasped and jerked under him. "Help me out here. Lean back."

"Castle, no, you shouldn't." Her protest sounded weak and unconvincing even to her own ears, and her hands were at odds with the words, fingers twining in his hair, pulling him tighter against her.

"The hell with shouldn't," he complained, shoving his hand farther inside her pants. His fingers rubbed across her, hard, and she gasped again, louder.

"You can't go back to work like this, can you?" he said against her neck, and she could hear the grin in his tone. The smug bastard. He knew just what he was doing.

And he knew just how to touch her, just how to scratch his stubble across her neck while his tongue painted words on her skin until she twitched and clutched at his shoulders, her breathing fast and erratic. So before she knew it she was moving to accommodate him: tilting her body back until he could get his tongue twisted around her breast; sliding her hips down the couch to give his hand better access. His fingers slipped and stroked through her like sweet torture, and his teeth closed around her nipple and she moaned his name when she came, writhing on his couch like a horny teenager.

Afterward, he sat up straight again, looking down at her with a small smirk on his lips but with that same strange look in his eyes that she had seen the other day. She sat up as well, trying to fix her clothing, staring at him. But she still didn't quite have the courage to ask, after the other day.

She could see his desire straining at the seam of his pants, but she didn't have the nerve to mention that either.

She kissed him quickly and went into his bedroom, grateful that she had a small stash of extra clothing here for, well, "emergencies." She found clean underwear and pants, and went into the bathroom to put herself back together.

When she came out, Castle was back in the wheelchair, looking out the window at the bustle of the city. She stood next to him for a moment, her hand on his shoulder, looking.

In the silence, she noticed a "For Rent" sign in one of the apartment windows across the way, and her eyes widened briefly with excitement. She made a mental note of the location, then carefully smoothed her expression and turned to meet Castle's eyes, his face turned up to her.

"You have to go," he said regretfully.

"Yeah." She sighed. "But I'll, I'll come back for dinner? If you want?"

He reached up and took her hand between both of his. "I do want. Always, Kate."

What the hell happened the other night? was on the tip of her tongue, but she still couldn't quite get it out. She felt like such a coward. She sighed again.

"Okay. I'll see you tonight, then." She kissed him once more and left.

On her way back to work, Beckett stopped in at the building next door and spoke to the manager, who gave her the contact information for the rental agent. A couple of quick calls from the car and matters were proceeding nicely.

"Everything okay?" Ryan asked quietly when Beckett got back to the precinct.

"Yeah. I guess," she shrugged. "I think he's just restless and cranky."

"Understandable," Esposito offered.

"I know, but it's only the first week. He's going to be insufferable by the end of the four weeks." Which reminded her that she would need to enlist the boys' help with her birthday surprise for Castle. She beckoned them into the break room and told them about her plan. Both were enthusiastic.

"Count me in," said Espo, and Ryan nodded.

"Definitely. This is going to be fun."

"Detectives," said Captain Gates from the doorway, "you've got a case."

"Think we'll need to get her in on it too?" Esposito asked sotto voce as they headed out to the new crime scene.

"Probably have to at least clue her in," Ryan opined. "Just in case."

"I suppose so," Beckett said, and then redirected their focus onto the real case at hand.

Getting the new investigation started took all afternoon, and Beckett had to call Castle and apologetically tell him that she would be late for dinner, but he took it in stride. "Alexis is here," he said, a little breathlessly, "and we're practicing with the crutches some more. She's quite the taskmaster."

"Don't let her tire you out too much," Beckett fretted, but she trusted Alexis to know her father's limits. In any case, it was only another half-hour before Beckett was able to call it a day, leaving the case in the hands of CSU and Perlmutter.

Dinner at Castle's loft was a quiet affair, involving takeout Indian food and a good deal of conversation about Alexis's college classes. Castle seemed his usual self: asking his daughter questions, quizzing Beckett about her college days, and recounting some college stories of his own, only mildly scandalous. By the end of the meal he had begun to slur his words and look a little pinched around the eyes, so Beckett made him take another painkiller and go lie down while she and Alexis cleared away the dishes.

This also gave them a chance to confer about the birthday mystery plan. Martha had filled Alexis in on the bare bones, and Beckett took her to the window to point out the vacant apartment, which she had already reserved with a substantial deposit. Alexis volunteered to get Castle a pair of binoculars, planning to present it as a joke gift to keep him entertained during his convalescence.

When they had finished discussing, and the kitchen was clean, Alexis gathered her things to leave. "I should say goodnight to Dad," she said, "unless you think he's fallen asleep?"

"Let me check," Beckett said, and tiptoed to the bedroom doorway, but Castle was sitting up in bed, playing on his iPad. Beckett gestured Alexis in, and then retreated to give them a moment.

"I'll see you tomorrow," Alexis promised when she emerged, and squeezed Beckett's shoulder briefly on the way out.

Thanks very much to all who have reviewed and favorited. I love hearing your thoughts so please don't hesitate to review or PM. There will be one more chapter, posted tomorrow.

A special enormous thanks to ipreferwestside for betaing and general encouragement/support!