She'd always questioned if the stallion she called "father" was really her sire. She bore no resemblance to him, though her sister seemed so share his exact blood. Whenever the topic arose in conversation, however, the subject seemed to be laughed at. "Of course I'm your dad, sweetheart! Don't be silly!". Lies. All of it. Lies.

It wasn't until the day her aunts Luna and Twilight came to the castle that she discovered the truth. "Come, Sunny, I've something to show you." she remembered Aunt Luna saying. She looked left and right, then waved for her neice to follow her. Soon they stood at the door of a dusty library.

"I can't tell you why I've brought you here, but it was to find something. I can't tell you what that something is. It's your job to find it. But you should know that I think you're ready to know the truth," And just like that, her Aunt left her stranded underground and facing what might be the biggest discovery of her life.

~

"You… TOLD HER?!" Twilight screamed at her wife.

"No. I simply" she gestured towards the secret entrance to the Canterlot undergrounds " led her to the library."

Twilight could simply sigh and try not to facehoof. "But- Luna, Honey, she's a princess. This could change her. Can we risk it?"

"Twilight, you didn't tell your daughter who her parents were until she was almost twenty. Astrea should have known before then, she should have been raised alongside our children."

Twilight's weakness. Mention of her former fianceè; Flash Sentry. The pony who now was trapped in Tartarus for the murder of her brother.

"Alright. But we can't tell your sister."

~

"Did you always know?" Sunny faced her former friend- now half-sister; with her face twisted in anger. "Did you always know about my father? King Sombra. Did you know he was corrupted? Tortured? Trapped forever in an evil shell, doomed to rot inside a body that wasn't his?"

Yes. Sunny heard Miracle's voice in her head.

I knew. But I couldn't tell you. And I still can't.

"You can't… what?"

I can't tell you the ending to his story. Or- the cliffhanger.

"What do you mean?" She started to be aggravated.

Miracle did the closest she could to a sigh, then closed her eyes.

He's still alive. Married, even. With a daughter. A daughter barely younger than you. He was rescued.