Some time later...
Eclipse paced back and forth anxiously with the others in the waiting room.
"I'm sure she's fine. It took me a long time to deliver her after all." Cadance smiled.
"But she's been in there for hours." Eclipse said worriedly.
"These things take time Darling." Rarity smiled as she worked on a baby blanket that was nearly finished for the occasion. Shining Armor nodded in agreement as he sipped a cup of coffee.
Applejack and Rainbow Dash had dozed off in a heap on the floor, Pinkie was eating a cupcake, and Twilight and Fluttershy were absently flipping through magazines to pass the time.
Finally a doctor came out. "Congradulations. You have a healthy baby boy, and your wife is doing fine. You can see them now, but please, just three of you at a time. They'll need to rest soon and they shouldn't have too much excitement."
Eclipse was going to go in of course, and the others decided that Cadance and Twilight could go in with him for the first turn. Flurry was laying in bed with a little foal wrapped up in a light blue blanket. "He's an alicorn, like us. Oh Eclipse, isn't he just beautiful?"
Cadance and Twilight gasped, for the tiny colt's coloring was a mirror image of someone they used to know quite well.
"He... He looks like..." Eclipse's eyes were wide.
"Aunty Luna, I know." Flurry smiled. "I think we should call him... Lunar."
Eclipse nodded, his eyes tearing up a little. "I think Mother and Aunt Luna would approve."
For just an instant both Eclipse and Flurry felt a strange shiver down their spines, but they both decided to ignore it, instead focusing on their little bundle of joy.
Celestia smiled. It was a smile that was wistful and a little sad. She'd thought that death would reunite her with her sister, but she'd been wrong. Somehow, someway, she was stuck here. Wandering around with nopony able to see or hear her, though sometimes they seemed to sense her. It was incredibly lonely, and seeing her loved ones grieve for her had riddled her with guilt. But... they seemed to be okay now. They were moving on with their lives. Still missing her but no longer with the deep mourning they'd once felt.
"Lunar... how fitting. How wonderful. I wonder if his personality will be as much like her as his looks are." She thought aloud as she slipped away, walking through the wall to sit outside and look up at the sky. It was a lovely night, and there was so many stars. The moon looked so bright! Then, suddenly, she could hear music. It sounded like someone was playing a harp. Then, there was the faint sound of someone singing, and she shot to her feet with a start. She knew that voice...
Celestia followed the singing until she reached the courtyard of the castle. There, Luna sat, playing a harp with her horn's magic. Just as she entered, her sister played the last few notes before standing. Her magic flashed, and the harp disappeared.
"Hello sister." Luna said gently, smiling with tears in her eyes.
"Luna! Oh Luna!" Celestia rushed forward with tears in her own eyes and threw her forelegs around her. "I have missed you so!"
"I have missed you too Celestia. Oh I am so happy to finally get to be with you again!" Luna sniffed as she held her back.
For a few minutes the two royal sisters just sat there, hugging each other and crying from the overwhelming emotions they both felt. But finally, they pulled back enough to look at one another and dry their eyes and faces.
"I... I don't understand. Why was I stuck here? Why couldn't I move on? Where were you?" Celestia asked anxiously.
"Oh Celestia, what you did was both noble in a way, yet oh so selfish. You made sure our little ponies would have a good ruler to guide them when you were gone, but at what cost? You seduced a stallion you did not love into marriage, and you had a foal only so that they could be your replacement. You have always been an upstanding mare, but what you did went against your principles. It went against everything you've ever stood for. You used these ponies only for your own personal gain." Luna said with a sigh.
Celestia hung her head and looked down guiltily. "I know. I'm so sorry. I was just so desperate to be with you again. I just wanted so badly to end the pain."
"Suicide doesn't end the pain Celestia, it just passes it on to the ponies who love you." Luna pointed out gently.
"I know... I know that now." Celestia said sadly. "So... what now?"
"You were stuck here for so long because you knew you did wrong. Would you really have been able to enjoy the afterlife if you were carrying this guilt? This was both your punishment and your redemption. You grieved with our loved ones for your mistakes, and then you got the relief of seeing them start to move on with their lives. To know those mistakes wouldn't haunt them forever." Luna told her. "And now... now you feel cleansed don't you? Of that terrible regret?"
"Yes. Yes I think so." Celestia nodded.
"It was holding you back, holding you down. But it's time now Celestia. It's time to come home." Luna smiled.
Celestia's heart flared with hope as she lifted her head to stare at her, wide eyed. "You mean... I can be with you now?"
"Yes sister. I've come to take you with me. All you need do now is follow." Luna opened her wings and jumped to the sky.
"I would follow you anywhere." Celestia's face lit up with the biggest smile she'd ever felt before as she spread her own wings. With a leap she flew after her sister. Luna laughed and Celestia laughed with her as they went up towards the Heavens, higher, and higher, until they were gone.
After a few days in the hospital, Flurry Heart and Lunar were able to come home. Flurry had settled Lunar down for a nap and was moving things around in a drawer, looking for a quill, when she came across a scrap of paper with familiar writing on it. She gasped as she read it, before snatching it up and rushing to find her husband.
"Eclipse! Eclipse look! Isn't this Starswirl's writing?" Flurry asked.
"Another prophecy?" Eclipse asked a little worriedly.
"I'm not sure. I think it's just meant to tell us that... everything is going to be all right now." Flurry Heart said as she held the note out for him to read it.
Eclipse hesitated, but stepped forward so he could get a good look at the words, his eyes misting over with bittersweet moisture as he read it.
And so the sun and the moon were reunited, to soar across the sky together forever...