The Earth was shrouded in clouds, a sphere of swirling blue and white. Given its position relative to the sun, it was wintertime. Around Christmas or New Years, perhaps. Wouldn't it be funny, he thought, if he descended upon Dib's backyard to find him standing right where he'd left him? Given relativity, it was possible. But there were new manmade satellites orbiting the blue planet, so he was certain that at least a few years had gone by.

"Heading down soon?" Tak asked, approaching as he gazed upon the planet suspended just beyond the main hold.

"Yes," he replied. "It's going to be terribly cold. No more PAK to help me regulate my temperature."

They were quiet, watching Earth's slow rotation.

"Are you sure he'll want to come with us?" she asked.

"Of course he will. The Dib-human would never pass up an opportunity to explore outer space."

"Then why are you so hesitant to go?"

He looked over at her, antennae springing up; it was always surprising how easily she could read him.

"I was a very different Zim when I left this planet. I don't know how exactly I should feel about coming back," he said.

"Then quit thinking about it and go. What will be, will be."

"I think you just want me to hurry up so we can go kill the Tallest."

She shrugged, a wry smile crossing her face. "Get moving. Your ship is already warmed up."

He shook his head and walked to the elevator. "Keep them under control while I'm gone."

"So, do what I always do even while you're here? Check," she said.

He rolled his eyes. She always had to have the last word. The elevator doors opened.

"Zim," she said, just before he could step inside. He turned and found her barely a step away from him. She put a hand on the back of his head and brought his forehead to hers. "You'll be alright."

He shut his eyes, feeling the warmth of her mind against his own. "I know."

In the hangar, his new VOOT was primed for takeoff, just like she'd said. He and Tak had modeled it after her own ship—it was more powerful than his old one had ever been. It flew smoothly from the docking bay and through the final stretch of darkness that separated him from Earth.

The moon hung brilliantly in the sky, the thick clouds highlighted like a soft, slow-moving sea below. He dove past them and was greeted by the golden, twinkling lights of the city—his city—blanketed with a healthy layer of snow. Headlights ambled along the streets that stitched all the neighborhoods together, the houses glowing more brightly than usual from Christmas decorations. It all seemed so two-dimensional after living so long in the multilayered traffic of Cyberflox. He flew over the cul-de-sac where his base used to be and hardly recognized it; the crater had been filled in, repaved, and redeveloped with houses that puffed smoke from their chimneys, warming the humans that lived totally unaware of him inside.

He finally spotted it: Dib's house. The lights were still on, so whoever was inside was still awake; he'd have to be quiet. He hovered over the backyard and set the ship down slowly, right in front of the garage. It could've been the exact point he'd taken off from.

The cockpit hissed open and the bitingly cold Earth air rushed in. It was uncomfortable, but Zim sucked it in all the same: snow, pine needles, wet asphalt, a hint of burning wood. Long ago, he'd convinced himself that he hated all those smells, but now they unwound a tension inside him he hadn't known was there. Instead of feeling shame or resentment or sadness at returning to Earth, he felt like he'd finally come back home.

But he couldn't stay for long. He stepped out of the cockpit, boots sinking into the snow with a satisfying crunch that only Earth snow could make. He stepped in the shallow remains of footprints that led to the back door from the cars parked in the driveway.

Cars? There had only been Dib's car the last time he'd been here. Now there were three, and none of them were the blocky black thing that Dib had driven them across the continent in. Then his eyes roamed up the trees near the garage; he was certain they hadn't been so large when he left. Suddenly the new satellites orbiting the planet and his completely restructured neighborhood felt unsettling. Zim's antennae sank to his skull as he returned his attention to the back door, the golden square of its window now foreboding. He walked up slowly, crouching on the stoop, and looked inside.

No one was in the kitchen, but he could see many people moving just past the doorway to the living room. One of them looked vaguely like Gaz, although with shorter hair. She brought a glass of something to another woman, who smiled and pressed her lips to Gaz's forehead. The Professor's hulking form passed by, but Zim couldn't be certain if it was him—his hair was far too gray.

Then a tiny human (a girl?) on undeveloped legs tottered into the kitchen for something, perhaps the plate of sweets on the table. Not two seconds later, a man came after her and scooped her into his arms. The little human reached for his glasses, but he offered her a small cookie before she could tug them completely off. A woman, different from the other two, came in and spotted him in the act; she put her hands on her hips in displeasure. The man just laughed, and when the woman reached for the tiny human, he handed her off. She smiled, said a few words, and pursed her lips. He leaned down and kissed her, his hand resting on the small of her back as they returned to the living room together.

Half of the window was fogged over from Zim's breath and he could no longer see inside. He staggered backward, heel slipping off the edge of the stoop; he fell into the snow, hissing at the burn as a few stray chunks of ice hit his face. He crawled hurriedly back to the ship and grabbed onto the lip of the cockpit, breathing hard.

"Ship," he said, still on his knees in the snow. "What Earth year is it?"

"According to data pulled from an orbiting satellite, it is Earth year A.D. 2022," the ship replied.

"2022," Zim gasped. "Th-that can't be right. It was A.D. 2007 when I left!"

"Well, Master, Cyberflox does orbit rather closely to a black hole. The laws of physics dictate that time would move more slowly there than on Earth."

"F-fifteen years," he stammered, though not from cold. "I…I've been gone for fifteen years."

"You didn't think to check before you came down here?"

"I don't need any sass from you right now!" Zim barked. He got to his feet, brushing away the snow before it could seep any further into his uniform.

The man he'd seen inside…could that really be Dib? His once gangly form had filled out, and what was left of his scarring was hidden by a dark, neatly trimmed beard. And that tiny human…could it be his, perhaps with the woman he'd kissed? Had the Dib managed to create a family in spite of his weirdness and his big head and the injuries Zim had wrought on his body? But, if Dib had a family, and if it really had been fifteen years…would he still want to go to space?

Would he even remember Zim at all?

A bitterly cold wind buffeted his antennae and sent the winter-stiffened trees creaking. He shivered and hugged his arms across his torso. Making up his mind, he reached into the ship and opened a panel to pull out the old leather CD case that had served him so well. There were a few more scratches in the old, smooth leather than when Dib had first given it to him, and a few of the discs tended to skip, but it was all still in fine shape otherwise. He followed his first set of footprints back to the door and set the case down gently on the stoop. He ran a hand over it one last time and returned to the ship. It was too cold to stick around any longer.

Then, from behind him, the creak of half-frozen door hinges. Zim's antennae stood on end, old instincts telling him to hide before his cover was blown. But instead, very slowly, he turned around. Dib was there, setting down a bag of trash as he bent to pick up the CD case. The glare from the kitchen lights behind him made his glasses look like perfectly round golden eyes as he turned the case over and over in his hands.

At last, Dib lifted his head. And they saw each other—they looked straight into each other's eyes, a chasm of silence between them. The snowflakes stopped falling, the wind stopped blowing, and even the Earth itself seemed to pause its path around the sun.

Then Zim remembered how to breathe and everything came unstuck again. All the grand speeches of victory that he'd planned on regaling his old friend with had slipped away, forgotten. They didn't really align with the new Zim he'd become anyway. So, instead, he said the most simple, natural thing that came to mind.

"Hello, Dib-thing."

The End

Author Note: There you have it! Another one done, just in time for the holidays. Thanks so much for sticking with these stories - it's been super fun writing them and a joy to share them. And yes, this is gonna be a trilogy! I have no idea when I'll start posting the final story, but it's in the works. Just make sure to follow me if you wanna keep reading! Thanks y'all, and TTFN!