A/N Thanks to SRAM and Happyface for the reviews. I so enjoy reading them and getting your views and input. I still own nothing.

**************August 9, 2015, 6:30 Pacific Time**************************************

Amy1 stepped forward, "Leonard4, we know how strange this all is, but I assure you, your daughter is all right. If you will come with us, we will explain everything."

He stared at her, "Amy, what are you and Sheldon doing here? Is this some kind of cruel joke?"

Amy stared at him, "I don't know what you mean. Why wouldn't we be here?"

Before Leonard could say anything, "Penny spoke up, "Please, Leonard, come with us, we need to talk."

Leonard looked back at her. He looked as if he was going to object, but said, "Okay, Penny, if you say so."

When they got in Amy's car, Penny and Leonard got in the back seat. He moved over and put her arm around her. At first she stiffened, but then leaned into him.

They drove in silence to the apartment. The moment they entered the apartment and were seated, Leonard spoke up, "Okay, I went with you. This better be good."

Sheldon told him the whole story. How the Leonard of their universe had been traveling to other universes exchanging places with the Leonard of that universe. How the transfers apparently lasted 28 days. He went on to say their hope was that the Leonards were then returning to their own worlds.

Leonard looked like he was going to interrupt but listened to the end. He sat back, "So I am the third Leonard you have encountered this way?"

When Sheldon nodded, he went on, "I have to admit, I find it hard to believe what you are saying."

He looked around, "But this room is different. There is nothing of Sara's stuff here."

"Let's say I believe you. So, in 28 days I will leave and presumably another Leonard will take my place." He smiled sadly, "You say you are assuming I will go back to my world but you have no way of knowing that. I could just as well find myself on another universe or just disappear."

Penny spoke up, "Don't say that. I have to believe this will all work out, that my Leonard will return at some point."

Leonard turned to her, "I'm sorry, I didn't mean to upset you. I must admit, there is a certain logic to it."

Amy spoke up, "Leonard, why were you surprised to see Sheldon and me? We are your and Penny's best friends."

He looked at her, "Sheldon and I haven't talked for three years."

They all stared at him. Finally, Penny was able to say, "Why? What could have happened to cause that?"

"Sheldon was never able to forgive me for what he perceived as ruining his chance for a Nobel Prize."

They all were stunned for a moment but then Sheldon realized what must have happened, "Was it because of what happened at the North Pole?"

Leonard looked at him surprised, "Yes. That happened here as well?"

Sheldon nodded, "But I came to realize that what Leonard did didn't affect the results. As difficult as it was for me to accept, I realized the project had failed." He sat back, "I even decided to accept his apology for not telling me until we returned home."

Amy spoke up, "What about me, Leonard? Did I still get with Sheldon?"

"Yes. You met at UCLA after Sheldon went to work there. You and he were married two years later."

Leonard thought for a moment, "I know this will sound strange, but it is gratifying to me that you and your Leonard are still friends. I would never admit it, but I have missed him."

After a long silence, each of them trying to absorb what had happened, Leonard asked, "So who lives in this Apartment?"

Penny spoke up, "You and I."

Leonard smiled, "I assume we are married."

Penny smiled back, "Yes."

Leonard turned to Sheldon, "So, where do you guys live?"

Sheldon answered, "Across the hall in 4B."

Leonard looked surprised but then turned back to Penny, "I assume we don't have a daughter."

Penny smiled sadly, "I am afraid not."

Sheldon asked, "Leonard, what do you do for a living?"

"I am an experimental physicist at Caltech."

Sheldon nodded, "Same as our Leonard. What do I do?"

"You are a theoretical physicist at UCLA."

Amy asked, "And me?"

"You are a doctor of Neuroscience at UCLA."

Sheldon said, "We do the same work here but at Caltech."

Amy went on, "Where do we live in your world?"

"In an apartment in Los Angeles."

After a long silence, Amy spoke up, "I don't know about everyone else, but I am starved. Sheldon, why don't we go pick up some food. Chinese, okay?"

Sheldon looked like he was going to object but Amy glared at him and they got the orders from the others and left.

Leonard looked over at Penny. Ever since he had arrived, he had sensed a sadness about her. He wanted to hold her, to try to comfort her, but if what they told him was true, this was not his wife.

He spoke up, "I don't know about you, but I could use a drink. Is there any beer?"

Penny answered, "Yeah. Could you get me one too?"

He nodded and went to the refrigerator bringing back two bottles. After they took a drink, Leonard hesitated and then said, "This must have been terrible for you."

Penny nodded. Then she turned to him, tears forming in her eyes, "It's been two months since I have seen him and I don't know if I will ever see him again."

Leonard couldn't stop himself; he had never been able to stand seeing Penny upset. He went over and sat beside her, taking her in his arms.

They stayed like that for a while. As he held her, Penny realized this felt different that when she had hugged the others. This man was married to his Penny, they had made love. She had given him a daughter. Suddenly she shocked them both when Penny leaned up and kissed him. Without thought he returned the kiss which quickly became passionate.

As his hand moved up and touched her breast, she moaned in his mouth. Then she broke away with a horrified look on her mouth, "My, God, what I am doing?"

She looked at him, "Oh, God, I am so sorry. I shouldn't have done that. I don't know what happened. I love my husband; I would never cheat on him."

Leonard was catching his breath, "I was going along." He sighed, "We were both caught up in the moment." He smiled, "After all, we are married." He looked at her, "It is apparent we need to be careful."

Penny was struggling to overcome her emotions, "I agree." She paused, "I don't know what came over me."

"I think it is just all that has happened. We were both missing our spouses."

Penny nodded.

Leonard asked, "Is there a place for me to sleep?" He paused, "Or do you want me to stay somewhere else?"

"No, you can sleep in Sheldon's old room, I think we know now what we need to do."

Leonard nodded.

As Penny lay in bed, she thought of what had happened between her and this Leonard. The scary thing was it had felt so natural to be in his arms. Was it because they were both married to their counterparts? This was the first Leonard that was married to her. She needed to believe that it would not happen again and that her Leonard would understand. Then a thought hit her. Sheldon's theory was that her Leonard was being exchanged with this Leonard. That meant her Leonard was with a woman that was married to him. Was he experiencing the same emotions?

No, she was not going to cheat on him and she needed to believe he would not cheat on her. After tossing and turning, she was able to fall asleep.

Leonard1 stared in amazement, he had a child? Who was her mother? He realized she looked a lot like Penny. He finally got out, "Hi, Honey."

The teenager spoke up, "Mrs. Hofstadter had to go to the store. She had me stay with Sara while she was gone. Now that you're here, I am going back upstairs."

Leonard was only half listening to her, "Yeah, Uh, okay. Thank you."

She looked at him oddly, but then said goodbye to him and Sara and left.

Sara spoke up, "Daddy, do you want to see what I colored?"

"Of course, Sara."

As he sat down beside her and looked at what she was doing, he was struggling to get his emotions under control.

Just then, the door opened and to his relief, Penny4 came in carrying a bag. She smiled when she saw him, "Hi, Honey, Hi, Sara."

Sara smiled, "HI, Mommy, Daddy was watching me color."

"I can see that."

After putting the bag in the kitchen, before Leonard realized what was happening, Penny came over and kissed him. When Leonard stiffened, she looked at him but then said, "How did it go at work?"

"Fine."

She looked at him, "Fine? I thought you had a big experiment today. You have been worrying about it for a week."

Leonard, flustered, finally got out, hoping he was right, "It went good."

Penny smiled, "Great."

She went on, "I am afraid supper is going to be a little late. Elise stopped by to complain and she was here for over three hours."

"That's okay, I am not that hungry."

"Are you sure nothing's wrong? You seem to be struggling with something."

"No, I'm fine. Maybe just a little tired."

She nodded, "Why don't you and Sara find something to watch on TV and I'll get supper ready."

Sara spoke up, "Can we watch Sponge Bob Square Pants?"

When Leonard smiled and said, "Yes," she grabbed the remote and found the channel.

As he was sitting there, he decided he should probably have Sheldon and Amy there when he explained everything. He smiled ruefully, if Sheldon and Amy were together in this universe.

He spoke up, "Is it okay if I ask Sheldon to come over? There is something I would like to discuss with both of you."

He was surprised when Penny turned around with a shocked look on her face. "Sheldon? When did you see him?"

Leonard wondered what was going on. He hesitated, "I ran into him."

Penny had put down the pot she was holding. "Sara, why don't you go to your room? I need to talk to your father."

"But I'm watching Sponge Bob."

"You can watch him another time. Now do what I say."

Pouting, "Okay, Mommy."

After she was gone and her door closed, Penny sat down by Leonard, "Okay, what in the Hell is going on? First, you act like you didn't want me to kiss you. Then you act like you had no idea what was going on at work. Now you tell me you talked to Sheldon. You obviously have something on your mind."

Her voice softened, "Did something happen? Please, Honey, whatever is it, we can work it out. Just talk to me."

Leonard took a deep breath, "Okay. You are going to have trouble believing what I am about to say, but it is the truth. I need you to trust me."

She looked surprised but managed to say, "You are scaring me. What is going on?"

He took her hands, "Do you remember me ever talking about Parallel Universes?"

She looked at him, what was he saying? Why was he talking about science?

"Leonard, why are you talking about that?"

He sighed, "Please trust me. Do you remember?"

"Yes. I remember. There are supposedly other world like ours." She hesitated, "Sheldon once spent time discussing it with me."

He took a deep breath, "Penny, I am not your Leonard, I come from one of those universes."

Penny first looked at him inquisitively, then her eyebrows rose and her eyes widened before they narrowed. "What the Hell, Leonard? You expect me to believe that?" She teared up a little. "Why are you doing this to me? Just tell me what's going on. Are you having an affair?"

"God No, Penny. Listen to me. I am from another Universe. That is why I stiffened when you kissed me. I am married to another Penny. That is why I didn't know what was going on at work. That is why I mentioned Sheldon. On my world we are friends and he lives across the hall with his wife Amy."

He looked at his watch, "About an hour ago, I replaced your Leonard."

Penny stared at him and realized he was being serious. She also realized that Leonard would never do something like this to her. But how could all this be happening. Then it hit her, "If you're not my Leonard, where is my husband?"

Leonard sighed, "I don't know." Seeing the look on her face, he hurried on, "We believe that I am exchanging places, that your Leonard is on my world."

He moved over and hugged her, "Let me tell you the whole story. I think it will help."

After he got a bottle of water and a still stunned Penny quickly downed a glass of wine, he told her how this was the third world he had transferred to. How it seemed that each one lasted twenty-eight days. That although they couldn't be sure, they believed that her husband would return at that time.

Penny listened intently. After he finished, she said, "You said you believed he will return here, but you don't know that for sure."

Leonard nodded sadly, "No, but it does make sense."

She nodded, "I have so many questions." Pulling herself together, she stood up, "But they will have to wait. Why don't you go get Sara and I'll get back to cooking. We can talk after she goes to sleep."

After they put Sara to bed, Leonard still marveling that he and Penny had a child, they sat down next to each other on the couch.

Penny started, "I think I know, but do you and your Penny have any children?"

"No."

She nodded, "From what you told me, its' been, what, almost two months since you have been home?"

"Yes." He hesitated, "And I don't know when or if I ever will."

"You must really miss her."

"I do."

He went on, "Can I ask you some questions about this universe?"

"Fire away. As long as I can do the same."

Leonard nodded, "What is the situation between me and Sheldon? Is he married to Amy?"

"I'll answer the second one first. Yes they are married."

"As for your first question, you and Sheldon have not talked for three years."

"What happened?"

"You went on a trip to the North Pole. Sheldon became convinced that you robbed him of a Nobel Prize by tampering with his experiment." She paused, "A board of inquiry found you innocent of doing so, but Sheldon remained convinced."

"Where is he now?"

"He lives in Los Angeles with Amy."

"Where does he work? Where does Amy?"

"They both work at UCLA. That is where they met."

"What does your husband do?".

"He is an experimental physicist at Caltech."

Leonard nodded, "So am I."

They sat for a while, both trying to absorb what had happened.

Penny broke the silence, "Does your wife work?"

"She's a pharmaceutical salesman."

Penny looked surprised, "Really, I just worked at the Cheesecake Factory before Sara was born. Now I am a stay-at-home mom."

"Penny did work at the Cheesecake factory before she found this job."

Penny stretched, "Well, I am sure I'll have a lot more questions." She hesitated, "What are you going to do about work?"

Leonard smiled ruefully, "I don't know. I guess I'll go in tomorrow and see if I think I can fudge it for a month. Do you know if your Leonard had any vacation time coming?"

"I think so."

Leonard nodded, "I'll see if I can find out."

Penny hesitated, "Have you thought about sleeping arrangements?"

"I suppose I could go to a hotel."

"You can't do that. It would upset Sara. She wouldn't understand."

"I can sleep on the couch." He found a smile, "I am sure he has done that sometimes."

Penny smiled, "Not often."

She looked serious, "But when he did, Sara was a little upset." She sighed, "We are two adults. We know what is going on. You need to sleep with me."

Leonard knew she was probably right. They could do it. It would only be a month.

After they got ready for bed, they awkwardly stood by the bed. Talking to Leonard had made Penny almost forget for a short time that her husband was gone but now it hit her.

"Leonard."

"Yeah."

"Do you think you could hold me?"

Leonard was surprised and then wondered if it was a good idea. But then he knew he needed it as well.

He reached out his arms and she snuggled up to him. They both were gratified and scared that it felt so right. They stayed that way for some time before breaking apart. They then got into bed, being sure to stay apart.

Saying goodnight, they both finally managed to go to sleep.