Equestria's Darkest Shadow

"Gone?!" gasped Princess Celestia. "How is this possible? Did nopony see who took her?"

"None!" reported the guard. "There were no sightings, no sounds, nothing!"

"There has to be at least some sort of clue!" suggested Starlight. "She couldn't have vanished into thin air!"

"All we could find was this note!" said the guard, and presented a small sheet of paper. Celestia took it and read it aloud.

"If you ever want to see Princess Luna ever again, you'll meet me at my home, the original Castle of the Two Sisters. No use of Rainbow Magic when we meet, or she gets it!

Signed, P. of S."

Then Twilight remembered something. "Wait! P. of S.?" she inquired. "Somepony used those initials when they wrote a letter to us!"

"Yeah! They were rambling about how 'friendship isn't real' and that 'our quest is utterly futile.'" added Rainbow Dash.

"Whoever this pony is will pay dearly for kidnapping my sister!" Snarled Celestia.

"Ooo! Celestia's getting edgy!" commented Discord, admiringly. "Now things really are getting exciting!"

"Don't worry, Princess Celestia." comforted Twilight. "We'll find Luna and bring this pony to justice." The others nodded in agreement.

"Thank you, my subjects. But to be safe, I feel I must accompany you on this rescue. We don't know what this pony might be capable of."

"If you insist." acquiesced Twilight.

"Have fun, everypony!" Discord called out. "I'll just stay here and keep the throne room safe from any intruders." He snapped his fingers and he was instantly in a Hawaiian shirt with two female ponies fanning him from both sides with huge fans. A butler pony came in to give him a drink. "Ah, thank you, my good stallion."

The others rolled their eyes. Fluttershy couldn't help but giggle.

"Why has he gotta be so quirky?" asked Starlight.

"Why? Because I can." answered Discord, and he laughed maliciously.

"Never mind him, subjects." said Celestia. "Let's focus on rescuing my sister."

The others agreed and set off for the old castle. When they arrived, it was dark and foreboding. Fluttershy felt a chill. "Oh. Th-th-this is much creepier than when we last came here." she shuddered.

"And much filthier." added Rarity. "Ugh! This could take days to get out!"

"Stand your ground, ponies." reminded Twilight. "We've got a princess to rescue."

"Yeah. So whoever this P. of S. dude is, bring. It. On!" said Rainbow Dash.

As if in answer, a giant cage appeared and trapped everypony inside. Twilight and Starlight tried to use their magic, but it vanished as soon as they used it.

"Grr! Why isn't this working?" growled Twilight. "What kind of cage is this?"

"It's a magic nullifying cage." came a familiar voice. Everypony's eyes widened with horror. Fluttershy turned pale. Suddenly, out of the darkness came a long and slender figure with two missmatched horns.

"DISCORD?!”

"Surprised?" chuckled the Spirit of Chaos.

"But...but I thought you learned your lesson from your ordeal with Tirek!" stammered Fluttershy in disbelief.

"Tirek isn't here anymore, my dear." He answered.

Fluttershy could only stare, mouth agape, unable to cope with anything going on.

"Ah'm not surprised that you'd be his P. o' S. feller writin' those letters," said Applejack. "But what's it supposed to stand for anyhoof?"

"Believe it or not, I'm not him." said Discord. "I'm just working for the guy."

"Then spill!" demanded Twilight. "Who is P. of S.?"

"The Pony of Shadows." answered Celestia. "It all added up when this place was brought up in that note."

"But we proved he didn't exist last time we were here!" argued Rarity, and the others agreed. "How could you know of him?"

"I'm afraid he's real. Very real indeed." said Celestia. "In fact, he's closer than you think he is!" and her voice got deeper with that line. Everypony watched in horror as "Celestia" was enveloped in a cloud of black smoke and became smaller to equal height of the others. And there, standing before the heroes was the Pony of Shadows!