Weeks later, after a third of the United States had been needlessly rendered unfit for life and a tiny group of American survivors had watched an alien spacecraft rise into the sky and disappear, Penny awoke in her new apartment (or flat, as it was called in London) and realized she wasn't doing herself any favors by moping and feeling miserable. Sheldon was gone— the harsh reality of those words ran her through every time— but there was nothing she could do to bring him back. He'd left her nothing but a statement of contrition, and she had no idea what to make of it; was he sorry for leaving, sorry for breaking her heart, or sorry because he'd had no choice? Would he have been allowed to stay if he'd wanted to? Did any of it even matter?

Penny's worries regarding the things told to her by the aliens gave her nightmares in which her soul was ripped forcibly from her body. Those with whom she shared her fears either gave her a pitying glance or stared at her in disbelief. Terrible rumors swirled through the newspapers, rumors alleging that there were never any aliens at all, that the entire thing was an elaborate ruse intended to give this country or that a justifiable reason to bomb the United States. Anger always bubbled up inside of Penny when she read the headlines, but ultimately it was fruitless to try and explain the truth. Only a handful of people close to her even believed her explanation of Sheldon's disappearance.

"He'll come back for you," Sheldon's grandmother would tell Penny every time she visited the older woman. She (along with Sheldon's mother and sister, and Penny's family) had thankfully escaped before the bomb dropped, and were given generous pensions and visas by the English government.

"What makes you believe that?" Penny would always ask.

"Because he loves you. I saw it in him, clear as day, that time you both stopped by. Them aliens may think he's theirs through and through, but there was only one man in my life that looked at me the way he would look at you, and that was my husband. He ain't gonna give that up, just like that. He has a plan."

During her most recent visit, Penny had sighed in exasperation and nearly spilled her tea in response to the woman's unyielding confidence in her grandson. "But you understand why I can't dwell, or hope, don't you? I can't spend my whole life waiting."

"Of course you can't, dear," Sheldon's grandmother said with a smile. "Go live. He'll find you."

And so Penny did live. She auditioned for plays in London and actually landed a couple of roles; the directors seemed to like her honest charm, and she loved being able to slip into someone else's skin, if only for a while. Howard and Raj visited once or twice a year (they'd found employment at a respected university in France), and when they were in town, Penny would eat pizza with them and play Halo as though nothing had changed. She took the train to her parents' small farm in southern England on the weekends and helped with chores. Her father, much to her relief, had lost his anger, and they spent many days reminiscing about Nebraska and cleaning shotguns together.

"You miss that boy, don't you?" Penny's father asked one night when he found his daughter on the roof of the house, staring at the heavens.

"This is the only time I let myself wonder about him," Penny murmured. "I do miss him. But it gets a little easier every day."

One autumn, three years after Sheldon's disappearance, Penny vacationed with Howard and Raj on the northern coast of France. They rented a cottage on the beach and spent their evenings lounging in the sand and drinking cheap French wine.

"You see, right up there is the Andromeda Galaxy, in the constellation Andromeda," pointed Raj, who was drunk and trying to impress two French girls that he and Howard had met at a nearby bar. Penny laughed and rolled her eyes.

"We have a friend there," Howard added casually. "He's an alien."

"C'est vrai?" One of the French girls asked. "Is it true? Did your friend kill the United States?"

"No, humans did that," Raj clarified. "But yeah. Maybe someday he'll come back with souvenirs."

"Or return for his lovely lady." Howard gestured toward Penny, and she gave him a small smile.

The French girls looked nonplussed. "You love the alien friend, oui?" One of them asked.

"I did," Penny agreed. "But I don't think he's coming back."

"So sad!" lamented the French girls. Penny looked idly upward and said nothing more.

"I'm hungry," Raj slurred after a moment of silence. "Who wants to go get crepes?"

The French girls squealed, and Howard scrambled to his feet. "Penny, you coming?"

"No, I think I'll stay," she said.

"All right." The group wandered noisily into the night, leaving Penny alone to appreciate the warm breeze and the comforting slosh of water against sand.

The stars twinkled brightly above Penny's head. She smiled as she remembered her night with Sheldon on the roof of his grandmother's garage. It seemed like a different life, like a dream. Maybe he was where he belonged, a traveler of the Universe he so dearly loved.

Penny suddenly felt very lonely. "Everything about my life has worked out the way I wanted, but I'm not as happy as I should be," she whispered. "If you're still out there, somewhere, I wonder if you feel the same?"

"I do."

Penny turned, and there he was, silhouetted by the light of the moon. His hair was longer and in complete disarray, and his clothing was tattered and worn, but it was him, it was Sheldon. He was holding a ridiculous bouquet of strange-looking flowers.

"These are for you." He took a step toward Penny and set the flowers down in front of her. "They are flowers from a planet with a name I cannot pronounce. Daily exposure to UV rays will ensure that they never wilt. They'll last forever."

"You've been gone for three years, and you thought it would be a good idea to bring flowers?" The emotions running through her were making her tremble.

"I know it isn't enough. I know you have no reason to accept the apology I gave you." He wasn't looking at her. "I came back as quickly as I could. The extra-terrestrials may have mastered faster-than-light travel, but the return trip was still incredibly long."

Despite everything that was running through her brain, Penny found herself saying, "I thought you told me nothing could travel faster than light."

"There's so much I didn't know... about physics, about the Universe. String Theory had only scratched the surface. There's so much more. I learned everything I could while the... my people were studying me."

"Have they decided to use our bodies?" Penny asked. "Is that why you're here?"

Sheldon grinned weakly. "No. I was ultimately a disappointment to them. They quickly discovered that a number of undesirable attributes unique to the human condition had rubbed off on me."

"Such as?"

"It would seem that I can, after all, be bothered with intimate socio-emotional interactions." He knelt down next to her. "Penny, I said those things three years ago because I was afraid of what would happen to you if I didn't agree to go with them. I was afraid they would simply annihilate both of us on the spot if I gave any indication that I wasn't what they were expecting. As it is, I was slated for 'recycling' when I managed to escape."

"Sheldon..."

He held up a hand. "Let me finish. I have not come here to ask for your forgiveness... I'm not asking you for anything. I'm here because I have spent the past three years feeling miserable and guilty and full of regret. Feelings that never plagued me before I met you. I've solved the mysteries of the Universe, visited a different galaxy, and encountered creatures unlike myself in every way... and yet I feel unfulfilled. You are the one great mystery of the Universe that I haven't been able to solve, or replicate, or find anywhere else." He rested his fingers atop hers. "Penny, I love you, and I was an idiot to ever make you think otherwise."

Penny didn't know if she wanted to laugh or cry or punch him in the face. Maybe all three. The Sheldon searching her eyes now was so different from the one that had left her years before; his experiences had given him an air of maturity and otherworldliness. But as he watched her anxiously and waited for a response, he reminded Penny so much of the old Sheldon that she could feel sad, nostalgic tears stinging her eyes.

"A lot of stuff has changed," Penny finally managed to say. "I've made a life for myself. I've... I couldn't wait for you."

"I never expected you to," Sheldon murmured. His voice had a defeated, tired tone. "I can't stay. I am certain my disappearance, as well as that of my pilfered ship, was noticed shortly after my escape. I have to keep moving to avoid putting this planet in danger." He gave Penny one final long look before rising to leave.

Penny felt the panic rise in her breast as she watched him walk away. The part of her that wanted to be bitter and prideful dissolved in an instant, and she remembered the words she'd uttered to the stars minutes before. She thought about the emptiness in her heart that persisted regardless of how happy she felt on the surface, considered the hundreds of nights she'd spent staring at the sky, wondering and wishing. Then, with a jolt of fear, she realized that she would regret it for the rest of her life if she missed this chance.

"Sheldon!" He turned, and she fumbled in her purse, looking for something. When she found what she was looking for, she ran up to him, grabbed his hand, and placed something in his palm.

Sheldon looked down. In his hand rested a tattered, worn piece of paper. The words written upon it were his own.

"I don't need an apology, Sheldon," Penny whispered through her tears. "I need you."

A huge, silly grin erupted on Sheldon's face. He gathered her in his arms and held her tightly, as though he was afraid she would disappear when he let go. Penny laughed and cried and kissed his face over and over.

"I really do have to go," Sheldon managed to say between kisses. "I have a plan that will prevent my kind from harming Earth, but it requires that I leave for a number of years. I want to stay, but it isn't possible right now."

"Then I'll go with you," Penny said. When Sheldon protested, she shook her head. "You don't get to make this decision for me. If we start to drive each other crazy, you can always swing by and drop me off at my parents' house."

Sheldon opened his mouth to respond, but the sound of nearby bellowing interrupted him. Penny looked over and saw Raj and Howard running toward them at top speed. The forgotten French girls trailed behind, munching on crepes.

"Dude, Sheldon, is that you?" Raj nearly tackled him to the ground. Sheldon chuckled and hugged his friend back.

"We thought you were a done deal!" Howard exclaimed, stepping up for his hug.

"I am most certainly alive and well," Sheldon said, smiling. "But I can't stay. I'm leaving, for the time being."

"We're leaving," Penny clarified. "He wants me to stay, but I'm going anyway."

Raj looked worried. "Hey, you'll be back, right? What do you want us to tell your parents? What about your flat, your job?"

"Tell my parents the truth. Tell the Air Chief Marshal what's going on, and he'll take care of the rest, I'm sure. And yeah, we'll be back."

"I have so much to tell both of you," Sheldon began. "The world of theoretical physics will be turned upside-down when I reveal everything I've learned—"

Penny elbowed him. "We have to go, remember?"

"Yes, yes. Goodbye. We will find you when we return."

"Wait just a second," Raj said, turning. "Hey, girls, our alien friend is here! You should come meet him!" He frowned when he heard the girls laugh and then point behind him in surprise. He spun around quickly, but all he could see was a vast expanse of ocean and sky.

Sheldon and Penny were already gone.

When Penny opened her eyes and shook the ringing from her ears, she was greeted by the sight of what she guessed was Sheldon's spaceship.

"Sorry, I haven't quite mastered the art of teleportation," Sheldon explained. "It's a rather convenient trait possessed by my kind." He held out a hand, and Penny took it without hesitation.

"So, where are we going?" She asked, intertwining her fingers with his.

"You'll see," he whispered, the secrets of the Universe dancing across his features. "You'll see."

fjdklajfkajfklajflsf DONE. HOLY CRAP, GUYS.

I spent a long time trying to figure out how I wanted this to go. In the end, I decided that these characters had been through too much crap to have an unhappy ending. Kudos to my1alias for basically nailing my idea on the head in the reviews.

Unsatisfied with this sugary-sweet ending? Want an epilogue detailing the space adventures of our dynamic duo? Do let me know!

Finally, thanks to the folks over at Paradox and all 140+ of you on here who have stuck it out to the end. This is the first real story I've actually finished writing in about twelve years, and I couldn't have done it without your support and encouragement. Expect much, much more from me in the near future!