When the Princesses- as well as all of the guards following them- heard the scream, they kicked it into overdrive. It was too late to stop Twilight from finding out, but maybe they could still console her and help her come to grips with the truth. Celestia cursed herself for leaving such a damning piece of paper in a library- no, in a book that Twilight was sure to read eventually. She may be a 'rule-follower', but her curiosity concerning facts would always win out in a battle with morals.
When they came into view of Twilight's home, Celestia silently commanded her guards to wait around the perimeter. She turned to Luna and Shining Armor and sighed. "Has Luna filled you in, Shining?" The stallion nodded, looking a little startled at the news, but taking it very well otherwise. "Good." Celestia said. "Then you understand the gravity of the situation on our hooves?" He gave a wry grin.
"Twili has always been a little melodramatic. I know what to expect." Luna raised an eyebrow at the Captain of the Royal Guard. "My sister accidentally burned one of our mother's favorite books when she was a filly." Shining explained. "She acted as though she had killed one of her classmates."
Celestia tried to stifle a chuckle. She turned to the door of the giant tree and tentatively placed a hoof in the center. As she pushed the door open, she peered inside. Finding no trace of the distraught unicorn in the room before her, she slowly trotted inside, followed by Luna and Shining. When the three ponies discovered that the ground floor held no ponies whatsoever- save themselves- they brought their search upstairs. They found Twilight in her room, her mane unkempt and her eyes bloodshot. She was curled in the fetal position, stroking her tail for comfort. They heard her mumbling inaudibly over and over. Shining pushed past the princesses and trotted over to his semi-catatonic sister.
"It's not true... Not true... No... No..." She violently shook her head. "Not true... Can't be true... Not possible..." Armor winced at the sight of Twilight. He reached out to put a comforting hoof on her back, but she scrambled away, shrieking at him.
"Twili!" He cried. He looked to the princesses for support, but they just stood there, dumbfounded. Luna's mouth stood agape as she tried to comprehend the situation before them. Twilight had begun to mumble again.
"It isn't true... You can't prove it... It's not true... No... Can't make me believe it..." Suddenly, she started screaming at them. "I don't care what the book says! It isn't true! It- It can't be true!" Celestia moved to Twilight's side. The crazed mare looked up at her teacher. Her voice became barely more that a whisper, and tears filled her eyes. "Is it true?"
Celestia nodded. "You are a direct descendant of the Draconequus Discord."
Twilight sniffled. "Am I- Am I evil?" She whimpered. Luna chuckled and came closer to Twilight.
"Dearest Twilight, you are incapable of choosing your own family." The Night Princess said. "Just because there is evil in your family's blood doesn't mean that you have to be evil." Shining looked down at his sister and smiled. She wiped the tears out of her eyes and stood on shaky legs.
"But how-" She paused, trying to form the question in her mind before continuing, which was proving to be an extremely difficult task. "How was a Draconequus able to-" Celestia sighed.
"The Draconeuuines, when they were plentiful, usually only had children within the species. But toward the end of their days, it was discovered that they were compatible with virtually every species in Equestria. In one year, Draconequus hybrids as common as the normal offspring."
"But then how are there so few unicorns in my family?" She asked.
"That's just the workings of Discord for you." She said. Twilight nodded. She reached out with her magic and levitated the page in front of them.
"It doesn't say who his mate was." She told them. "All that it says is 'Nondescript Alicorn'." Twilight paused. She looked from the page to Celestia and back to the page. Something clicked in her brain. "Celestia?" She whispered. "Did you and Discord ever-"
"What?" Celestia cut her off. "No! Never! Not even once! And even if I wanted to, which I don't, he is way too old for me." Luna giggled.
"Yes. You just keep telling yourself that, Sister." Celestia shot a nasty glare at Luna. If looks could kill. Twilight thought.
Shining spoke up. "Well then, who could it be?" He said. This was becoming very puzzling. The princesses shrugged.
"We have no clue as to who Discord's first wife may have been. It's actually pretty surprising that anypony was able to tie him down in the first place." Celestia said. Twilight reached up and tapped Celestia's shoulder. "What is it, my Faithful Student?"
Twilight gulped down the fear that was building inside of her. "Can I- Can I see him?" She asked. Celestia looked as though she was going to say no, but thought better of it.
"Of course you can Twilight. I suspect that you have a lot of questions, and even though he can't answer them, I'm sure that at least getting them off of your chest will help you come to terms with your lineage." The three of them helped Twilight down the stairs and out the front door. Once there, Celestia stopped, puzzled by another thing. "Twilight? Where is Spike?"
"Oh!" The unicorn giggled. "He's spending the night with the Cutie Mark Crusaders at Rarity's house." She said. Celestia nodded. As they trotted out, Twilight noticed all of the Royal Guards surrounding her building. "Um... Princess? Why are they all here?" Celestia blushed slightly.
"N- necessary precautions." The Sun Princess stammered. She couldn't help it. Twilight fell to the ground, laughing her flank off. The laughter was infectious. Within seconds, all four of them were rolling on the ground, giggling, laughing, chuckling, or chortling. Soon, the Royal Guards began to feel the effects of the laughter as well. An entire group of about seventy-eight ponies were all laughing, waking a nearby neighbor.
"Quiet!" The disgruntled mare screamed, which only elicited more laughter from the ponies.
As she regained her composure, Luna turned to Twilight. "Would you like to fly to Canterlot, or shall we take the magical route?" She asked. Twilight smiled.
"Let's fly." She said.