Twilight was sitting in the bath when Spike received Celestia's summons. Spike had moved in with Twilight in the library once more, despite his obvious desire to stay with Rarity and Twilight's protests. He insisted that Twilight would be utterly lost without him and wouldn't even know how to feed herself, but Twilight was more sure he just didn't want to leave her side, and felt a little guilty about making her bleed from the face. She was going to visit Rarity that day, try to find the dream-poison, and wanted to feel fresh and rejuvenated before convincing her friend to let her dig through her possessions, looking for it. She'd moved back to Ponyville, and found settling back in to be a little difficult, but not impossible. Most ponies accepted that the other Twilight had been an impersonator, and were willing to give her another chance, while others treated her with a guarded suspicion that had only dissolved in recent months. Spike pounded on the door to the bathroom, “Twilight! A letter from Princess Celestia!”
Twilight sighed, “Put it on the table, Spike!” She called back, determined to get some good out of the bath. She may not be able to linger as long as she'd like, but generally the Princess was understanding of delays. A few moments later though that hope was smashed when Spike pounded on the door again.
“Twilight! Some Guards are here for you, said they came to help take you to Canterlot!” So much for relaxing. Twilight dried off quickly and teleported downstairs to find two Royal Guards waiting stoically outside the front door. She telekinetically grabbed the scroll from the table and nodded to the Guards, who turned towards the waiting chariot.
“Spike!” Twilight called over her shoulder as she walked out, “I'm leaving immediately, I'll probably send back for my things in a few hours! Don't hold up dinner for me, I'll be a while!” Spike called back a distant affirmative, and Twilight was soon safely aboard the Guards' chariot, flying at an exceptionally high speed towards Canterlot. Twilight tried to ask the Guards what the rush was about, but they either couldn't hear her, or were instructed not to tell her. Stymied, she broke the seal on the scroll and read her mentor's message.
My most faithful student,
I realize this is most irregular, but a situation has arisen that requires your unique capabilities. A crime most heinous has been committed here in Canterlot, and it defies even the best magical investigators. I fear the involvement of the Beast, but so far none of the rest of the investigators can find any sign. When you land, Lieutenant Pumpkin Spice will be waiting for you and will fill you in on the situation.
Lieutenant Pumpkin Spice was a vast disappointment to Twilight, who had been reading entirely too many mystery books in her spare time and had expected somepony dashing and gritty, with a sort of rough handsomeness about him. The Lieutenant looked like a unicorn that was couple meals shy of healthy, with a beige coat, cropped brown mane, deeply circled brown eyes and a general look of disreputable-ness that made even the Investigator's garb look shabby. He was dressed in a lighter version of the Royal Guard armor, with an under-barding that included chainmail and pockets for important evidence. He was waiting between the fattest earth pony she'd ever seen and a grim-looking green pegasus. “Lady Sparkle,” The Lieutenant said respectfully, “I'm Lieutenant Pumpkin Spice, this is Sergeant Cupcake,” He indicated the fat earth pony, “and Sergeant Garland.” The green Pegasus nodded curtly.
Twilight stepped down from the chariot and nodded to the three Guards, “Thank you Lieutenant, now where are we exactly?” Twilight hadn't really been to much of the noble portions of Canterlot, preferring more plain surroundings to do her late night studying, but the area they had landed in was definitely upper class, judging by all the marble and granite. The Lieutenant jerked his head in a direction and started off once Twilight was walking beside him. He didn't start talking until they were out of earshot of the chariot, and even then he was speaking very quietly so she had to lean closer to hear.
“We're in the Gemstone district, and the place we're going to is around the corner here. The Princess wants this very tightly under-wraps, so please, Lady Sparkle, I ask that you keep this discreet.” Twilight nodded uncertainly as they stepped up to the Guards standing in front of a taped-off alleyway. Lieutenant Pumpkin Spice showed his badge, and Twilight was instantly recognizable, so they were let through with no challenge. Once they were in the alleyway, Twilight understood the need for discretion, and only her experiences in the Hedge kept her from losing her lunch right there.
A unicorn had been crucified to the dead-end of the alleyway by spikes, then somepony had, with great precision, opened the abdominal cavity and pulled out the viscera and knotted it with apparently some care. Then the pony had been flayed, postmortem, with great exactitude, and the face had been removed, leaving only bare skull and staring eyes. The flayed skin was nailed to the wall to give the appearance of wings, making the dead unicorn look like a twisted, macabre parody of one of the Princesses. The intact eyes, which were a heartbreaking blue, stared sightlessly down at Twilight almost accusingly. As if to add to the horror, somepony had scrawled a poem in the blood on the wall, which Twilight read mechanically,
Dear Celestia, full of grace,
Help this pony find his face,
If you do,
I won't come for you,
But with twelve more,
I'll be at your door.
“We've already moved the other victim,” Sergeant Garland said seriously, his eyes flinty as he looked at the horrific scene, “Stabbed several times by the attacker, she was obviously left for dead once the attacker had heard the approaching Guards. She should be coming around soon.”
“Other victim?” Twilight asked distractedly, staring at the flayed pony, “Who?”
“Karat Ring, the victim's wife.” Twilight looked up to the flayed pony skull, saw the gold marriage band there and found a deep well of anger rolling up from inside her. She felt her mane start to ignite slowly, and very carefully damped it down, forcing herself to be objective.
“I'll want to speak to her once I've finished my investigation.” Twilight said, feeling the shadows start to whisper to her as she gathered her magic for the spell she was forming in her mind, “I'm going to need her statement, and the statements of the first Guards on the scene, as well as anypony else who was involved.” She felt, rather than heard the affirmatives behind her and ponies moving to obey, and was about to order something else when she noticed a slight tingle from elsewhere in the alley. She held up a hoof to keep Pumpkin Spice back, and walked over to a doorway almost hidden in the darkness, where the shadows whispered to the purple unicorn the strongest. She felt her mane ignite again into purple flame, and the shadows cling to her hooves adoringly. She knocked on the door, kicked it open and found herself looking into the Hedge, just as she'd feared. She turned, blocking the doorway from the curious Lieutenant's eyes, and frowned at him, “And somepony send a runner to the palace with a message for Princess Celestia. Tell her Twilight Sparkle needs iron to deal with her investigation. She'll know what I mean.”
The site of the investigation soon became a hive of activity, with Guards coming and going with equipment and cameras. Princess Celestia herself visited briefly but didn't say much, she just looked at the crucified pony with an unreadable expression, then nodded to her student and reminded her to visit soon before she teleported out. Specialists were brought in, ponies with investigation cutie marks were constantly going over the notes, and yet somehow with all this activity going on none of the newspapers or magazines so much as noticed. Twilight was beginning to suspect that Celestia was leaning on the media to keep things quiet, which was a mildly disturbing thought, but for now it worked to her favor.
“Lady Twilight,” Lieutenant Pumpkin Spice interrupted Twilight's train of thought, causing her to turn irritably. The Lieutenant brought forward a clipboard with his magic, “I have the results from forensics here,” Twilight's irritation evaporated and she turned fully to face the beige unicorn, “No hoofprints, no residual magical traces, nothing.” Twilight stomped with annoyance, but before she could say anything, the Lieutenant flipped to the next page of his clipboard, “Also, Miss Karat is conscious and would like to talk to you.”
“Miss Karat?” Twilight asked, confused.
“The other victim, Lady.”
Now Twilight remembered, and she nodded to Pumpkin Spice, “Alright, where is she?”
“Canterlot General Hospital, do you want an escort?” Twilight just shook her head and teleported out, leaving Pumpkin Spice to sigh and continue the grim duty of taking pictures of the horrific scene.