A/N This is the first chapter of the second part of this story. If you have not read the first part - The Momentum Conservation Part 1: Action and Reaction – you will almost certainly be confused. Sorry, but I couldn't really make this second part self-contained, as it follows naturally from the events in Part 1. And I didn't really think it useful to try to provide a thumbnail summary of all 23 chapters in Part 1. The action begins the morning after the last day of Part 1.

Penny lay awake in bed, remembering the conversation of the previous evening. Momentum, she thought; and momentous. Were the words related, she wondered? But she saw the way clear now: they would be married, and soon. And they both wanted to start a family, also soon. Wow. She shook her head in wonder, and smiled in quiet delight, as she got out of bed silently so as not to wake Leonard. She wandered down to the bathroom and then to the kitchen.

Sheldon was sitting on the couch, reading; Penny started in surprise to see him – he usually left with Raj for work by 7.30 and it was now after 8. "Sheldon, you're here! Is everything all right?"

"Yes, I decided to take the bus today. How are you?"

"Just fine," Penny said cautiously. She knew from experience that there had to be a reason for the change in routine. But she wanted to ask him something anyway. "Sheldon, I have a question for you. You know so much about everything, I figured you were the right one to ask." More flies with honey, she thought.

Sheldon smiled: "Ask away."

"Well, I just read Wuthering Heights and I really liked it."

Sheldon interrupted, "Ugh. That sentimental claptrap? Well, I guess it takes all kinds…."

"Whatever. I liked it. Maybe it's a girl thing. Anyway, I want to read something else that's similar. What would you suggest?"

"As I say," Sheldon continued, pedantically, "I regard it as sentimental claptrap. But there are certainly similar novels. The obvious place to start would be with Jane Eyre."

"Who's she?"

"Not who," Sheldon said impatiently, "what. It's a novel by Emily Brontë's sister, Charlotte. Same general idea. Those who like the genre argue about which is better between the two novels, so if you liked one you'll probably like the other."

"Oh. OK. Thanks!" She waited for Sheldon to tell her why he was really there. She didn't have to wait long.

"Penny, actually I stayed here to talk to you. By the way, I see you've been getting up earlier, which I have to say is a pleasant and welcome surprise. Anyway, I wanted to ask you about the situation between Amy and me. I'm very puzzled about her intentions. I thought we were an excellent couple, an opinion confirmed by objective tests; but apparently she does not agree. Can you tell me what her problem is?"

"That's not for me to say, Sheldon. I think you two have to talk about it between yourselves. I know Amy is not willing to talk to you yet, but I think she will eventually. And when you two do talk, I think it's important for you to listen to what she has to say."

"OK," Sheldon said, "but this implies that she should listen to what I have to say, too. It's inappropriate for her to cut off communication and then expect to be the only one communicating."

"Well, you know what they say: all's fair in love and war. It's not about what's fair, it's about her feelings."

"What about my feelings?" Sheldon said, starting to get angry. "I have feelings, too!"

After making the obvious crack to herself, Penny said, out loud, "Of course you do. But sometimes you may not be that good at expressing them. It would probably help if Amy had more of an idea of what's going on inside you."

Sheldon sat, clearly thinking about something. "I wasn't going to do this," he said finally, "but I can't see any reason not to. When all this began I started writing down my thoughts in a log. I only did it for a couple of days, until you two came home. But I wonder if you can read it and tell me if this is the kind of information that might help Amy understand why she's making a big mistake?"

It was all Penny could do to keep from responding – it seemed Sheldon still was putting all of the blame on Amy – but she did want to see the log, and she did also want to help her friends. "I'd be happy to read it, sweetie. Where is it?"

The lanky physicist walked over to his desk, picked up his laptop and brought it over to Penny at the kitchen high-top. He opened a file and, wordlessly, put the laptop in front of Penny. She read:

Sunday. Two days ago Amy Farrah Fowler (henceforth AFF) informed me that she felt she needed to take a break from our relationship. The following day, I received a text from Penny about an incident they had experienced on their way to Las Vegas. The text was vague, but it was easy to infer that Leonard had been seriously injured. Today I find myself in an unaccustomed emotional state. I am unable to focus on my work, as my mind wanders incessantly. This log is an attempt to arrive at an understanding of my state of mind: its causes, effects, and implications. I recognize that emotional insight is not my strong point – and if I did not, I certainly would know it, as AFF has pointed this out to me more times than I care to remember – however, I feel a need to arrive at a more complete comprehension of the situation.

The catalyst is clear: the three people closest to me have, in various ways, abandoned me. AFF's actions are the clearest type of abandonment. Indeed, I regard them as close to a betrayal. After years of encouraging me to be open about my feelings, she has suddenly decided to shut off all communication. This strikes me as completely unacceptable and, moreover, very unfair to me.

The situation with Leonard is different, of course. I do not really know what happened to him but it certainly does not appear to have been intentional, other than the obvious point that they could have planned their wedding more appropriately, and he could have taken better care of his car so that it would not have broken down, leaving them open to whatever attack later transpired. Leaving that aside, I do understand that Leonard and Penny's absence is not intentional. Nonetheless, the fact that they are not here is, I believe a part of my distress. Leonard has always been my principal confidant when it comes to issues that arise with Amy, and Penny has often served in something of a supporting role. I do respect their opinions about my social interactions, inasmuch as I have come to recognize that my views and behavior in this regard are in the tail of any population distribution.

With this in mind, I will analyze my emotional state with regard to recent events. Central to this is Amy's sudden and unexpected announcement that she was "taking a break," from our relationship – an ambiguous concept if ever there was one, but nonetheless one whose central meaning is quite clear.

In this regard, I find myself torn. For the past several years I had developed a what I thought was an internally consistent understanding of my relationship with AFF. We began as friends. Over time our social interactions revealed a commonality of interest and enthusiasms that suggested general compatibility. It became clear roughly three years ago that AFF was desirous of traditional forms of intimacy. My own views on this are undoubtedly affected by my psycho-emotional peculiarities, of which I am well aware. I do recognize that my general tendency to avoid physical contact is outside normal ranges, although I do not regard the tendency as pathological or even particularly troubling. However, I realize that for AFF this restricted the enjoyment of our relationship. As a result, I made an effort to overcome my reticence and engage in some form of physical intimacy. I did discover that kissing could be pleasurable.

An additional part of the general evolution of my understanding of pair-bonding relationships was a recognition of the almost undeniable existence of the elusive notion of romantic love. Although the psychological content of this concept remains unclear to me, it is impossible for me to deny that I have had feelings for Amy that could not otherwise be explained without recourse to the notion of love.

But this leads to another aspect of my reaction to the situation. In the context of a relationship that I felt it was based on mutual understanding, it is hard for me to see a legitimate reason for AFF to separate, even if this is only temporary. I do understand that she would like to see changes in aspects of my personality that stand in the way of her satisfaction, and that may impede her ability to realize certain desires – by which I mean not only carnal desires but other desires associated with an intimate relationship. However, over the years I had come to think and expect that she would be sensitive to my makeup, and to my own needs, and would be able to adapt her expectations accordingly.

This appears to have been a mistake. It is conceivable, of course, that upon reflection in this temporary break AFF will determine that the benefits of our relationship outweigh the costs. However, the mere fact that she needs to "take a break," presumably to reconsider the costs and benefits, is troubling to me. It is especially troubling that she appears not to have accounted accurately for the many positive features of our relationship, and for the great benefits she has realized from associating with me. I had always felt that she appreciated me and my contributions; now it appears that I may have been mistaken. As I consider the implications more fully – in particular, her apparent disregard for the assistance I have given her over the years – her behavior is beginning to anger me.

Monday. I had a difficult conversation with Penny today by video-chat. She did not give me details of events in Barstow but it became clear over the course of the conversation that Leonard was much more seriously injured than I had thought. Apparently the injuries were life-threatening, although he is currently out of danger. I will admit that my conversation with Penny affected me more than I had anticipated. I was already emotionally distraught when we spoke – in fact I had not been able to update this diary all day, as I had been unable to concentrate on much other than attempting to deconstruct the meaning of AFF's words to me, and the appropriate reactions to them.

Penny was her usual emotional self. But there was a tone of seriousness to what she said to me that caught me off guard and that indicated to me, even before she said anything, that Leonard may have been close to death. The prospect of this disrupted my thinking further. I had never really contemplated the possibility that Leonard would not be available to me as friend and confidant. Indeed, the prospect of his moving across the hall was difficult for me to accept. Thinking about his death gave me great pause. I found the resulting interaction upsetting, involving a dramatic upheaval in previously predictable social relations.

I had resolved before our video chat that I would attempt to control my emotions, and to respond in a socially appropriate way to whatever Penny wanted to talk about. This was not easy. She began by telling me quite emphatically that she would be staying with Leonard to care for him. This of course was the sort of revelation that caused me distress last summer. However, as she said, the circumstances were extenuating. She did offer to have the two of them stay in her apartment, but I felt that it would be more appropriate to offer them the opportunity to stay in Leonard's. I also agreed to abide by a series of other demands that Penny made. I recognize that they were not unreasonable, if in fact his condition is as severe as she has led me to believe. Nonetheless, it was not easy for me to accede to these requests.

Towards the end of the conversation I became quite emotional. This was principally the continuation of my distress about the situation with AFF, but as I had not mentioned this to Penny I carried on as if it were about what had happened to the two of them – which was not entirely inaccurate. I do not think it appropriate for me to engage Leonard and Penny in conversations about my difficulties with AFF, at least until I have formulated a course of action on my own. However, this may be difficult, especially as in the past talking with Leonard and Penny has facilitated my understanding of the psycho-emotional issues at stake.

Monday evening. It is now midnight and I have been unable to sleep. I have played over in my mind a series of interactions between AFF and me, in an attempt to understand the source of her dissatisfaction. I do understand now that AFF construed my interruption of our fifth-anniversary kiss-fest with a question about The Flash television show as a lack of interest in and attention to her. It was certainly not intended as such: the issue was important to me, and I value her input. Nonetheless, the misunderstanding is now clear to me. I am having more trouble with other interactions that appear to have been cause for dissatisfaction, and I feel that Leonard and Penny will be able to provide insights that I cannot entirely capture.

I have in any event resolved that my relationship with AFF is important to me. This means that I should exert effort to attempt to keep the relationship active. However, this faces the apparent fact that part of AAF's concern is that she believes that I do not care sufficiently about our relationship. I need somehow to find a way to indicate to her that I do very much want us to be together.

However, I am also angered by AAF's treatment of me. She has behaved as if I were a common suitor, obligated to obey trivial norms of politesse and emotional massage. This is not in my nature, and I resent the implication that I should be forced to alter my very nature in order to satisfy another individual – especially one who, although intelligent, is clearly not at my intellectual level.

At the same time, it is hard for me to imagine my life without AFF in it. And I am coming to grips with the fact that this will require sacrifices on my part. The benefits of our relationship are great; the costs to me of making the compromises and concessions necessary to sustain it are also great, but I believe they are worth it.

I do not know how I can possibly address these issues if AFF refuses to speak to me. And her refusal to do so is definitely inappropriate and unfair. She seems intent on gaining advantage in our relationship, and this makes me extremely uncomfortable. It has always been clear who has been the intellectual leader between us, and I see no reason to alter this component of our relationship. If AFF would like to reconsider other aspects, I am open to that possibility. But to simply shut off communication is childish.

Tuesday. Leonard is coming home today. I feel that I need to talk to him about the current turn of events. I understand from Penny that he has trouble speaking above a whisper, but that is not a major issue. I do think that he would be able to give me some insight into why AFF has reacted with such hostility to me. I do understand that I have done things to anger her, but I cannot imagine what might have provoked so extreme a reaction on her part. It seems likely, given past experience, that Leonard would have an idea.

Penny looked up from the laptop. This was as much emotion as Sheldon had demonstrated in the previous five years combined, and she wanted to tread carefully. "Sheldon, I'm so sorry this has been so difficult for you," Penny said. "And I'm really sorry that we weren't here to help you get through a tough time. But we're here now."

"Thanks. I know you couldn't help it, but it made things very hard for me. Especially with Amy being so unreasonable. So do you agree with my analysis?"

Penny hesitated. "Look, this is really between you two. It's not about who's right or wrong, it's about what works. I don't think Amy is being hostile, as you put it, just out of spite. I think she's unhappy about some things. And if you want the relationship to work, you'll have to try to figure out what will make her happier. You'll have to figure that out together – it's not something you can just decide on your own. Do you see that?"

Sheldon bristled. "But what about my happiness? What gives her the right to make decisions that affect both of us without any consideration of my perspective? Look at you: you're waiting on Leonard hand and foot. Why should Amy suddenly decide that she's too good to worry about my well-being?"

Penny had to force herself not to respond in kind to Sheldon's outburst. She knew he was upset, and angry – and, generally, clueless. She tried to be helpful. "I know you're angry, and that's all right. You can tell Amy how you feel. But you also have to pay attention to how she feels. Both of you are entitled to your feelings."

"Well, why is she entitled to refuse to talk to me? That's not right."

"She needs time, Sheldon, time to think. Try to respect that. In fact, try to respect the fact that Amy is a strong, smart, woman who wants to be happy. There's nothing wrong with that. I think what you want to be trying to figure out is how you can help her be happy, not how she can make you happy. A relationship has to involve give and take."

Sheldon was getting increasingly agitated, "I've done nothing but give, give, give for five years. And then she decides on her own that it's not enough. That's wrong. And I resent your taking her side."

Penny blanched. "Sheldon, I'm not on anyone's side. I want you both to be happy. And believe me, I really want you two to be happy together. I'm just trying to give you some insights into what Amy's thinking and feeling. I'm sorry if you feel that's unfair, but seriously, if you really want to work things out with her, you're going to have to accept that her feelings are just as legitimate as yours."

Sheldon was silent, but his eyes flashed defiance. Finally he took back his laptop and walked over to his desk. He turned to Penny. "I appreciate your giving me the female point of view. It helps me round out my analysis. I have to go to work now. I'll see you this evening. I'm going to the comic book store but I thought I'd at least have dinner here, if you don't mind."

"Of course not, Sheldon. You don't have to ask; this is your apartment." Penny was startled by the bitterness of his tone.

"Oh, that's right, isn't it? See you for dinner." And he walked out the door.

Penny sank into the armchair, feeling defeated. She had tried to have a serious conversation with Sheldon, but it had just seemed to infuriate him. She needed to talk to Leonard about it, but he probably wouldn't be up for another couple of hours. In the meantime, she brought up the online text of Jane Eyre and began to read.

Over lunch, she told Leonard about her conversation with Sheldon. The situation was worrisome. At some level, it seemed, Sheldon was in over his head: facing relationship demands that he might not be capable of meeting. But they knew he really cared about Amy, and didn't want to lose her.

"His pride is probably the main obstacle here," Leonard mused. "He just can't bring himself to admit that she might be right about something so central to their relationship. The question is, how can we help him see that he needs to compromise more than he has been, without his feeling like we're attacking him?"

"Based on my experience this morning," Penny sighed, "it won't be easy. Maybe you can try talking to him this evening? He's coming home for dinner before going to the comic book store."

That afternoon Penny was in the living room reading, and enjoying, the beginning of Jane Eyre, when Leonard stumbled in, looking very shaky. "What are you doing up?" Penny demanded, slightly irritated. "You know you're not supposed to get out of bed by yourself." He had fallen once, and the doctor had given strict orders.

Leonard simply stood in the hallway and Penny immediately saw the now-familiar look of terror in his eyes. He had had another one of his daytime nightmares. She rushed to him. "I'm so sorry, honey. Did you have another nightmare?" She put her arms around him and led him to the armchair. "You're safe now. I'm sorry I yelled at you. Do you want to tell me about it?"

His hands were still shaking, she noticed as she held them. He shook his head a little. "Just a bad memory. This time I was looking everywhere but you weren't there. I could hear you calling for help but I couldn't find you," he murmured. "I'm sorry I got out of bed, but I had to find you."

"That's all right, I'm here now." Penny was starting to worry about these nightmares. This was now the fourth, and they did not seem to be fading in intensity. She was glad they were seeing the doctor the next day, so she could ask for advice. For now, she knew only that she wanted to bring Leonard back to a happier place. She hugged him close and kissed him softly.

After a few minutes his heartbeat was back to normal, so she reminded him of their conversation last night. "Honey, do you remember what we talked about last night? About getting married, and starting a family?"

"Sure," Leonard answered with a smile.

"It made me so happy to think about this morning. Not just because it's, you know, exciting, but because I really feel like we're so on the same page now. You know?" She asked, somewhat tentatively. In truth, she felt the need to confirm her feelings.

Leonard nodded with great certainty. "I do. I feel like we are really taking a big step forward, and we're really ready for it." He paused. "That raises an issue we've sort of been avoiding. What do we do about living arrangements? About Sheldon?"

Penny exhaled slowly. "I know. And he's so confused and stressed out right now. I can't imagine having a reasonable conversation about it until things are worked out with Amy. So maybe we just have to wait to talk to him. But we can still think about our own plans, can't we?"

Leonard was silent. "I'm a little tired of working so hard to adapt to Sheldon. It's been really great this past week to have our needs come first. Of course, that won't last, but it gives me a taste of how life could be. I mean, we're adults now, not graduate students, and I think it might be time to insist to Sheldon that he act like an adult, too."

"Whoa, that's moving pretty fast. He is your best friend, after all. And he's going through some hard times. So be nice. He's going to want to talk to you about Amy, and he really needs your advice."

Leonard sighed. "All right. But somehow it seems ridiculous that after what we've been through, we have to walk on eggshells around Sheldon."

They sat quietly for a few more moments, after which Leonard recommenced, more brightly, "I want to ask Dr. Sussman tomorrow if I can go out soon. I'm getting a little stir-crazy. You must be, too! Don't you want to go out and do something? I'll be fine alone. Or if you worry, I'm sure Howard or Raj would be willing to baby-sit me. You need to go do something fun, Penny. I worry about you being cooped up here with a boring invalid."

Penny looked at him and smiled. "I know you do. But this has been one of the nicest weeks of my life – I mean, leaving aside changing bandages and things like that. No work, just talking to you and reading. I'm happy here."

"All right, all right. But your parents are coming Saturday, and you have to show them the town. You mom's never been to LA. So you have no choice. For at least one day you're going to need to find me a baby sitter. How about Sunday? Howard and Raj don't have to work, they could stand guard or whatever it is you think needs to be done when I'm here alone."

"I'll admit that makes sense. I'll talk to Howard. I would like my parents to see a little of LA, although they keep telling me that the only reason they're coming is to see us and help out."

She led Leonard back to the bedroom and they discussed more of their plans for Penny's parents' visit before Leonard starting nodding off. He was still only good for a couple of hours at a time before he got tired. Penny went back to reading her book, but this time by Leonard's bed. She didn't want to risk his waking up from another nightmare alone.

A few hours later, Penny heard Sheldon come into the apartment. Leonard had just woken up, so she warned him and then went out to the living room and announced that she was going to make him spaghetti with little hot dogs cut up into it – his comfort food. Sheldon was surprisingly unexcited. Penny nonetheless followed up on the plan she and Leonard had worked out: "Hey, can you do me a favor? Leonard's been lonely all day. Could you talk to him?"

"Hey, buddy!" Leonard said enthusiastically as Sheldon entered his bedroom. "It's been so long since we've had a chance to talk more than a few minutes. How are you doing?"

"Fine," Sheldon said, unconvincingly. "Actually, not so fine. I'm spending a lot of time thinking about this situation with Amy. It's distracting me from my work, and it bothers me."

"I can understand that. It must have been a shock when she told you she wanted to take a break, right?" Sheldon nodded. "What do you think brought that on?"

"I know the proximate cause – it was that incident about the Flash TV show, you know the one we talked about before you two went off to get married. But that hardly seems like enough to warrant this kind of hostility."

Leonard waited to see if Sheldon was going to take his thoughts any further, but his friend was quiet. "Umm…do you have any ideas about why she might feel the way she does?"

"How should I know?" Sheldon said with irritation. "She's refusing to talk to me."

"What about before that? Were there things you think she was unhappy about in your relationship?"

"No! Well, apart from the obvious, her obsession with physical intimacy. But I thought we'd reached agreement on that, about going slowly. Other than that, I thought things were fine."

"Do you think she maybe wanted to move faster, not just on physical intimacy but on other aspects? Like maybe spending more time together?"

"She never mentioned it," Sheldon said, again sounding irritated. "And she knows full well that any complaints can and should be raised in the appropriate venue. We had just had an annual review, and there wasn't anything serious that I could see."

Leonard wasn't sure where to go from here. Sheldon appeared totally baffled, and Leonard didn't want to be the one to force him to confront the fact that Amy clearly wanted more romance, more attention…just, more. But Leonard couldn't figure out how to get his friend to a more constructive place without a little prompting.

He tried again. "I know that when Penny's been unhappy with me, it's usually because she feels I'm not taking her feelings into account. Can you think of anything that Amy might have been feeling that might have benefited from more of your attention?"

Sheldon snapped, "Amy's not Penny. If she has feelings, she should tell me about them. I'm not a mind-reader. Maybe Penny can talk to Amy and find out what is really going on. Since Amy refuses to talk to me, I don't know what else I can do."

Leonard resigned himself to failure. "That could be a good plan. I'm sorry I can't help more, Sheldon. I wish I could. You know, I just want you to be happy and I really am sorry to see you unhappy."

Sheldon looked sharply at Leonard, once again. "I'm not unhappy. My happiness doesn't depend on anyone else, certainly not Amy. I'm just trying to understand where she and I stand."

"Oh, OK. I'm glad to hear that." Leonard gave up. "But anytime you want to talk, I want you to know that I'm here. Actually, I don't have much choice these days – I'm always here." No reaction. Sigh, again. "Come see me anytime, Sheldon. I miss talking to you."

"Penny's making me spaghetti with little hot dogs cut up into it. I should go eat." And Sheldon got up and left the room, leaving Leonard shaking his head.

Later that evening, as they prepared for bed, Leonard reported on his conversation and asked Penny about dinner. "He didn't say a word. And he looked angry. Barely thanked me for dinner and then went out with Raj to the comic book store. I didn't see even see him when he got home; I think he's been locked in his room. What a mess."

"I know," Leonard shook his head sadly. "But there's little enough we can do. How about our little talk? And something that's not about Sheldon, please…."

"OK, then. Let's talk. Leonard Hofstadter, where do you see us in ten years' time?"

"Still thinking about last night's conversation, huh? All right, let's do this. I see us in a small house in Altadena. And two kids, a boy and a girl. And you're making your next movie but it's here in LA because your contract specifies that you can't be away from your family for more than a week at a time. And I have tenure at Caltech and lasers are just so 2015, so I'm working on something that hasn't been invented yet. And I get home from work first but the kids are already home with the baby-sitter, and I read the boy's homework and look at the girl's drawings and figure out what to make for dinner because you promised to be home by 7. How does that sound?"

Penny was smiling broadly. "You've got it all worked out, don't you? It sounds like something out of the 1950s. But it does sound wonderful. I'll have to remember to put that clause in my contracts. Just one thing," her eyes narrowed, "who's this baby sitter?"

"Oh," Leonard hastened to clarify, "she's a 63 year old Ukrainian woman who's wonderful with the kids and brings us lots of home-cooked food."

"Quick thinking, mister. Anyway, I do love the way you think. And I do love you."

"Me too. But I think we have to start practicing to produce those two kids, don't you?"

"Ha! Any more practice and I think we'd be perfect, and who'd want that? But you drive a hard bargain."

"So to speak," Leonard replied with a wicked grin as Penny turned off the light.