"Nothing under 'U'", Pinkie Pie said, popping out from behind one of the numerous bookshelves. "Nothing under the 'S' either."
"Why were you checking under the 'S' section?", Twilight asked.
Pinkie narrowed and shifted her eyes back and forth, crouching into a lower stance. "Shadow Ponies."
Twilight couldn't help but to facehoof. "Pinkie, my brother isn't a Shadow Pony. That means Sombra probably isn't one either."
"Ah still can't believe yer brother is the same species as Sombra", Applejack said, putting another book back on its shelf. "Never woulda thought."
Twilight sat down at one of the crystal tables that filled the library. After the discussion with her friends and Princess Luna about her brothers' true nature, the search for information had begun. Not much was known about Sombra, nor the Umbrum in general. While the Princesses went down to check Sombra's Quarters in order to find information, the six of them had come to the Imperial Library in order to look for information that might help them find either of them. So far, that search had turned up nothing.
"It's not like it changes anything", Twilight said. "He's still my brother."
"Of course, darling", Rarity said, pulling out and checking another book. "It's just... Well, we've never heard of Umbrum before this, and it was a bit of a shock."
Rainbow Dash came down from her flight, landing next to the table. "Nothing on the top shelves. 'Least nothing about this."
Before any of them could say anything, a set of approaching hooves caught their attention. Amythest Maresburry, the librarian, came around one of the bookshelves, smiling at the group. "Oh, hello dears", she said. "What can I do for you?"
"Do you have anything on Umbrum?", Spike asked, only to be met with a glare from Twilight.
Amythest's calm smile was replaced by a worried frown. She cast her head around, before leaning forward and whispering. "Pray tell, why do you want to know more about... Them?"
The Element Bearers and Spike exchanged looks, a silent debate going on between them. Finally, Twilight turned back to Amythest and replied, "We're looking for any information we can on King Sombra. We... still don't know what happened to him."
"Ah", the elderly mare said. "Well, I'm afraid you won't find much in the main library. Follow me; I'll take you to the Archive."
Following behind her, she led them back toward her desk by the front of the Library. They passed several other Crystal Ponies, who flashed smiles and sent friendly waves in their direction. As the ones who restored the Crystal Heart and arranged the first Crystal Faire in a long time, they were well-liked among the locals.
Behind the desk, they found a camouflaged door, which Maresburry opened with a simple key. She led them into a small room, filled to the brim with cabinets and shelves. Leading them to the back of the room, she opened one of those cabinets, rooting through the papers.
After a moment, she pulled a collection of leather-bound books and loose papers out of the cabinet. Passing them to Twilight, she said, "These are some old reports from the Crystal Guard and a few anatomical reports. I'm afraid this is all we have left."
"What do you mean, 'all you have left'?", Fluttershy asked.
Amythest Maresburry sighed, lowering her head. "After Ki-After Sombra staged his coup, he had most of the books about Umbrum brought to him. Historical records, Speculative Texts; even some foals books. After a few days, he had them... Burned."
"Burned!?", Twilight yelled, face absolutely aghast.
She nodded somberly. "He called them slander and lies. He laughed as his Mercenaries set them ablaze." She sucked in a deep breath, letting out a slightly wheezing breath.
"W-well", Twilight said, still reeling from the revelation. "How much can you tell us? Surely, you remember something."
Amythest sighed, nodding ever so slightly. "Of course. Even when you get to my age, you don't readily forget. But, perhaps we should go outside? I don't know about you, but I don't think standing around in this dusty room would be the best place to explain."
"Ditto", Rainbow Dash said, wiping a dusty hoof on her coat.
With agreement from the others, they made their way out of the archive. They circled back up the second floor, finding an unoccupied table to sit at. As Amythest sat down shakily, she said, "Sorry. I'm not as spry as I used to be."
"No worries", Applejack said. "Shoot, mah granny is one a' the toughest mares ah know, and she's pushin' a hundred."
Amythest laughed, before leaning back in the seat. Once again, her smile faded into a small, tight frown. "Well... It's been a while, but I remember the basics. Our ancestors came here, fleeing from Discord as he ravaged Equestria. They... What are you doing?"
All eyes fell on Twilight, who met them with quick, jerking motions. Her eyes fell on the scroll and pen she had summoned, before letting out a nervous giggle. Spike said, "Don't mind her. Tell Twilight not to take notes during a story is like telling a fish to stop swimming."
"Hey!", Twilight said, before sighing. "That's fair. Anyway, go on."
"Right", Amythest said, clearing her throat before continuing. "Anyway, our ancestors founded several settlements, carving out a home in this place. The initial plans were to stay here until Discord was stopped, but... Well, this became our home. We just didn't know this was also the Umbrum's home."
"They attacked us without warning", she said, removing her glasses. "They would... Surround whatever they sought to attack, and tear it to pieces. They were compared to wolves; ravenous beasts that showed no mercy."
Fluttershy seemed to fold herself behind her mane, a nervous look on her face. "W-why?"
"We don't know", Amythest said. "Maybe they wanted us to leave. Maybe they just wanted us dead. All I know, is that it led to almost a decade of near-constant conflict. Conflict that claimed the life of our first Empress's consort. Using her grief, and her continued love for her people, she created the Crystal Heart."
"As you know, it is an artifact powered by strong love. The love of her ponies, as well as her love for them, created a force that could slay the Umbrum. Love like that; it was an anathema to them. She used to protect us, and eventually banish the Umbrum. It became our sword, and then, after the war was over, it became our shield."
"But, what happened afterward?", Twilight asked. "How did Sombra end up here?"
"That, I'm afraid no one knows", Amythest said, shrugging her shoulders. "We don't know how any Umbrum got out, let alone as a foal, like he was when he was found. After that... Well, I don't know. None of the Crystal Ponies really know what Sombra had us do... But I shudder to think about it."