It came silently. It had to, happening 91 million miles away, with the silently screaming void between them and its source. Despite this, that it happened was beyond denial. They were approaching the rock that barely peeked from the snow, already half buried in snow. It had taken them about ten minutes to get there, cold and miserable, as that world would have it.
A brightening, the world around them slowly becoming more visible through the snow as the sun pressed through the cloud cover above. He paused, looking up at the injured sun. "What? Did..." He shoved Umbra harder than was needed. "What's going on?"
"I know as well as you do," Which clearly wasn't much. That it was brighter seemed hard to argue. "Um... Here we are." She started brushing snow off her ticket home, clearing the way with great tossed of the fluffy powder that had stacked on it but hadn't had time to get too heavy.
"The gods are cruel... and we are foolish." He sighed heavily. "They had such a simple request, and we were stubborn, until the last..."
Umbra paused in her digging. "You think the sun's fixed?"
"I think it is, but the gods are wiser than we would be." He waved around at the lit snow. "It won't be fast. That would destroy the world. It will return as slowly as it left. I will be dead before it finishes becoming warm. This planet will be restored, and live without humans to bother it." He laughed at the bitter irony of the whole thing. "Perhaps what we deserved."
"Look." Umbra set her hands on her hips. "From what you've said, you weren't here when that happened. Don't take responsibility because some ancestors were dumb. You put it right, take pride in that." She hoisted a thumb to the sky. "Even if we're not here, this planet will be put back right, and you did that."
"So..." He came closer, sweeping away snow as she had been doing. "This will go to your world, somehow?" All he could see was the stone they were digging up. The portal was invisible from that side.
"You're alright with this?" Umbra resumed throwing snow aside, clearing the way. "You still want to go?"
"Why wouldn't I?" He shrugged with a misted sigh. "This world will be fine without me, but I'm out of food. I go with you, or I die. It's a miserable choice, but it doesn't sound that bad." He gasped, drawing in chilly air as his hand vanished into the stone itself. He yanked it free with a hiss. "Is this it?"
Umbra shuffled in next to him, brushing snow along the way. "Good job. One last thing, to be sure you understand. You will come out of this with hooves and a tail."
"Better than dead." He vanished, diving into the stone. Umbra shrugged to the empty world in recovery and slid in after him.
She hit the ground on all four hooves, flicking her returned tail. "I'm back!"
But attention was on something else than her. Celestia and Morning were peering at the new pony. They were snow white in appearance, with tinges of soft cyan blue around their unshorn fetlocks. The signs of cold weathering flecked over their form, and they were looking around with wide eyes.
Celestia's horn glowed as she placed a tarp over the mirror, closing it. "Welcome... Do you have a name?"
"Anik," offered the new pony, looking around in a slow circling. "And you are... Celestia?"
Celestia smiled brightly at that. "Did Umbra tell you that?"
"Umbra." He turned back to her. "That's your name?"
Umbra scooted over to Morning, scooping her up into a hug. "It is, and this is Morning, my daughter."
"Charmed." Morning was watching intently, as if ready for Anik to do something strange.
Anik rubbed his cheek softly, more interesting than usual as he used the hoof he never had before. "It's..." Hot? It wasn't hot, but it was a lot warmer than he was used to. "Is this what life used to be?"
Umbra extended a wing towards Anik. "It was just like it looked like. Humans in that world messed up really bad and got punished. He was the last one serving the sentence."
Celestia flinched back at those unyielding terms. "What was the sentence?"
"Death, or change. Either option being... painful." She shook herself out, but no snow had come with her. "A very cold and slow one at that."
Anik reached for Morning, just to be snapped at, enough to make him reconsider that option. "If she is a child, and you... And me? I am like an older brother." He laughed at that, a deep and true sound. "My name has a meaning, you know."
Celestia nodded. "You will find that most pony names have literal meanings. While other races use words they have long forgotten the meaning of, the pony language has only changed in written form, its spoken form remaining largely stable." She gestured in the air as she explained this. "So, Celestia." She gestured at herself. "And Umbra." She turned that hoof on Umbra. "And Morning." To the small filly. "We are named as we are. So, please, what does your name mean?"
Anik's mood had turned to the positive, unable to hold his vision on any one thing for long. "It means brother to a woman." He looked to Umbra. "I had thought you a lady, but you are more than that." His eyes went up along her. "You are large enough to be my mother easily, and you, my savior, have a daughter."
Umbra blinked softly, putting that together. "Meaning... you are a brother to Morning."
Celestia inclined her head. "I do not want to abandon you. You have my support in this, but it was your decision that brought him here."
Umbra shook her head slowly. "No! No, that's fine. I have... I can take care of him, and he deserves someone to do that." She floated Morning up to her back to ride her as was proper. "Warning, you are too large for me to want to give casual rides to. Learn to use those new legs of yours."
"I wouldn't dream." One could see that Anik was indeed dreaming that. "I owe you everything, as a son should their mother. What do people do in this world?"
Umbra considered her new son. "What did people do in your world?"
"Survive." He sank to his haunches, mood punctured a moment. "But that... What do you do here? I have died, and this is heaven. Do people eat? Do they drink? Are we... past these things?"
Celestia wriggled her nose. "I should imagine not. Eating and drinking are two pleasures most ponies share. If you don't do either, you will not be long for this world.
Anik suddenly hopped to his hooves. "What does your name mean?" he asked of Umbra. "You said they were words, like mine. What is an 'Umbra'?"
"Shadow," she replied, shadowy magic billowing from her in a threat of darkness that abated after a moment, her eyes glowering with that dread energy.
"Too poetic." Anik leaned back. "In the darkest day, the very last, a shadow came to me. She wrapped me in comforting darkness, delivering me... And with her passing, light returned to the world."
"You are wise to understand mother's generosity." Morning looked on from atop Umbra. "I never had a brother... I had expected them to be an umbrum." But she didn't deny it. She was adopted as well. "I may be smaller than you, but I have seniority."
"What is that?" he asked guilelessly. "I had a mother once... She was all the family I knew. She told me many stories, but..." He shook his head violently. "I will not carry her ghost here. Mother Umbra, what do people do here?"
Umbra patted her new son on the shoulder. "We live. We don't have to struggle so much to get food and water. If a pony does their best, they can expect the others to provide enough to survive. Do you have any idea what 'money' is?" His clueless stare was hint enough. "It's what we trade with."
"Oh!" He threw his backpack to the ground and... discovered that hooves were not hands, frantically trying to search the bag with them and an absence of any progress.
Celestia's golden glow encompassed the bag. "May I?" When he nodded, she gently turned it upside down, letting the things inside tumble to the ground. She didn't lift the bag, not letting anything fall far before resting on the ground. She set the bag aside, mostly empty.
"Thank you." He was able to hoof around, pushing things aside until he found a necklace. "To trade with." He hung it off a fetlock, lifting it into view. "Mother said they used to trade a lot... when there were more people. Give something, get something."
Umbra nodded at that. "Exactly. Bits are just a specific thing we trade." She floated out a bit into the air. "They're nice because everyone wants them, so you can trade them with someone you may have nothing else they want."
Celestia cleared her throat softly. "As Umbra suggested, we do offer a stipend to anypony who is doing as their cutie mark demands of them." That got another blank look. "You have no idea what that is, my apologies." She turned to present her rump, her magic forming an arrow to point at the sun symbol that adorned it. "My cutie mark. Most ponies have one by the time they are an adult. It is a reflection of your true calling. Mine is the sun. I rise and set it every day."
Umbra displayed hers. "I'm tied to this--"
"You are a... rock? A shiny rock." He was trying so hard to figure it out, but with little luck.
"It's a heart, a crystal heart." Umbra turned back to facing him directly. "Morning doesn't have one. She isn't a pony."
Morning tapped at Umbra from above. "You aren't a pony either, mother."
Umbra blinked softly. "Wait..." Oh... "I'm an umbrum too..." She looked back at her rump. "What is that then?!"
Morning looked back to that crystal heart. "It's what you decided to have, mother. We can look however we want to."
Umbra sagged with a little laugh. "Wow... Um, well, I like it, so I'm keeping it."
"I don't have one of those." It was true. Anik's rump was with no marks. "Am I an 'Umbrum'? What is that, a kind of pony?"
Morning huffed at that. "Don't be insulting. Umbrum are a different species. Predators." She flashed her dangerous teeth. "We feed on fear and terror. We are creatures of nightmares."
Anik flinched back at that description. "Oh... So...."
"You are not an umbrum," assured Umbra with a smile. "You don't have one yet because you haven't figured yourself out. It will come to you if you explore this world and learn more about it. Until then, you are my son and I will care for you, so don't feel bad about it."
"Yes, mother." Anik pranced in place in a moment of giddiness. "This has been the best day in a very... very long time." He turned to Celestia, dipping his head at her. "Thank you for tending to the sun."
Celestia pricked her ears. "You're quite welcome... Hm, it's been some time since somepony said that so directly. Anik, you must be confused, being in a new form."
"I had accepted death." Anik raised his head. "This is better than that. Every breath that doesn't burn with the fire of ice is a gift. Every unburdened beat of my heart, to be cherished." He raised a hoof to his chest, feeling that soft thumping. "Every word, an impossibility. It thought I was alone, forever..." A tear escaped him. "My entire life is a blessing. A new life, a new self... I will learn it."