NIGHT. TIME UNKNOWN.

Twilight woke with a small start and a fair bit of annoyance. Her sleep had been interrupted again. The door closing behind the Nurse had made a loud slam. Twilight groaned then rolled out of bed, landing on her hooves. She went at a trot downstairs and wondered how well Spike was doing. She looked out a window. seeing the night and the rain, when she had reached the main room and wondered how long she had slept. There was a small note from Nurse Redheart on the table. Twilight noticed that the Nurse had used Twilight's new "Typewriter" that had been invented recently to write the note. Only unicorns could write proficiently without that Typewriter, but now Earth ponies and Pegasi were writing too, which had made the library in Ponyville grow substantially. The note read:

To Twilight Sparkle

Spike's condition has improved drastically, and there should be nothing that shall not heal naturally over some time. Please send word if there are any complications.
- Nurse Redheart

Hmm, Twilight thought. There was double the work Nurse Redheart had to do these days, after Nurse Tenderheart had retired. No wonder she had had to leave Spike with her a while. Twilight might as well get a snack while she was here, she thought as she began to busy herself with making something to eat.

Pinkie was trotting slowly to the library, carrying some cupcakes. She wondered how she was going to do this, and how she would make it seem like Twilight had just left or something. She was friendly with Celestia, after all and it wouldn't be helpful to have her poking around... Celestia had no number. Pinkie could see quite easily that she would never be able to get near Celestia, and her magic could always overpower Pinkie at any time. She wasn't sure if Celestia even could die. But why was she thinking about Celestia? It was Twilight she needed to concentrate on, and work out some sort of plan...

Twilight had just finished eating and was sitting with a book at Spike's side.

... the dragon has three kinds of flame, that which can send items through the place of magic to where they wish them to go, one that is simple, unmagical fire made by a combustion of gas in which the dragon uses a small biological item akin to flint to spark the gas and send out a flaming gas, and the final kind which...

There was a knocking at the door. Twilight wondered if Nurse Redheart had come back for something and she shut the book, trying to keep her page number in her mind. When she had gone downstairs and opened the door, she saw an uncomfortable looking Pinkie Pie carrying two satchels by her side, soaking wet.
"Pinkie." she said in a flat voice. She hadn't forgotten Pinkie's attitude about Spike yesterday.
"Um... hiya, Twilight." Pinkie said. She looked very tired, worried and sad. Twilight was feeling slightly sorry about her, but tried to quash that small feeling. Even though Pinkie was one of the last friends she had now, with many of her old friends gone and Twilight being a general hermit to most of Ponyville, she didn't want to be too nice to her. "Do... do you think I can come in please? Only it's a bit wet out here..."
"No, really? Fine, come in but try and not drip on any of the books."
Pinkie walked in slowly, her straight mane dripping on the floor.
"Is... is everything going alright with Spike, Twilight?"
"Yeah. He'll be fine soon enough."
Pinkie went to a small table near a lectern and took one of the Satchels off. She took out a tray of cupcakes and laid them on the table.
"For you and Spike." she explained. Twilight felt a bit better towards her now. It seemed that Pinkie did actually care about Spike. She still wasn't sure what caused her behaviour in the Everfree Forest though. Maybe Pinkie was suffering from losing her friends too. Pinkie eventually became as much as a hermit as Twilight a while after Applejack had left for New Appleloosa and had her train overturn. Most ponies were actually shocked and amazed at this, and chalked it up to her feeling horrified over Applejack's death. There were no more parties.
"Thanks Pinkie. Er... sorry about shouting at you in Everfree. Are you alright?"
"Yes, Twilight. Now why don't you eat one of those cupcakes?"
"I'll save them for later if you don't mind Pinkie. Spike should enjoy them when he wakes up."
Pinkie was giving Twilight a glare. "I would really, really prefer it if you ate one right now, Twi..."
Twilight wasn't quite ready to trust Pinkie again, and she was being rather creepy again and reminiscent of what she was like inside the Everfree Forest. "No thanks, I said."
"Hmm."
"I'll go take them up to Spike. He can have them straight away then."
Twilight picked up the cupcakes and went to take them up to Spike.

Pinkie was seething downstairs. Twilight didn't trust her, she could tell. She could see the ghost ponies pressing against the windows of the library, and she could see some of the shadow creatures hanging over them. She just hoped... nonononono!

Something snapped inside Pinkie's mind.

"Alright Pinkie, is there anything else you came-" Twilight said as she came out of Spike's room. Then stopped. Pinkie was staring out the window, looking utterly shocked and terrified. Twilight went over to the window and looked outside. "Uhh, Pinkie? What're you looking-" then she screamed and spun around. Pinkie was standing behind her. There was a long cut in Twilight's flank, cutting right through her cutie mark, and Pinkie was holding a knife in her mouth and staring at Twilight. Her eyes were bloodshot and she was moaning through the knife in her mouth. The other satchel she had been carrying was on the floor and Twilight thought she saw metal gleaming inside. Then Pinkie charged at Twilight, flicking her head to the side, trying to gash her with the knife. Twilight quickly ran back up the stairs, her mind in a state of shock and sudden turmoil and trying not to feel the pain from the cut. What was happening? What was Pinkie doing!? What was she going to do!?

Pinkie stared at the stairs a moment before walking slowly up them. She had to kill Twilight NOW, before anything worse came from the darkness and tore at her. She knew this wasn't a dream, and that she had to feed the numbers...

Twilight had found herself in Spike's room. The little dragon was muttering in his sleep and smoke was curling out of his nostrils. Twilight didn't know what to do. Then the door was pushed open and the demented Pinkie walked in slowly.
"P-Pinkie, what are you doing!?"
Pinkie adjusted the knife in her mouth and said "What I've always done Twi. But you never realised."
"What?"
Pinkie said nothing but got closer. Twilight started to panic, and levitated some of the books to make them fly off the shelves. Pinkie moved quickly out of the way the falling book pile and ran at Twilight. She rammed headfirst into Twilight, knocking her over.
"Pinkie, stop!" Twilight shouted
The noise had woken up Spike, who was staring wide-eyed at the general carnage around him. Smoke had begun to gather in clouds around the ceiling, as he started to panic as well.
"Stop messing around Twilight, I mustn't annoy the numbers again." Pinkie said, baffling Twilight. "Just stay still and this will be over."
"What will? What!?"
Pinkie aimed a stab at Twilight's shoulder, and Twilight moved quickly to dodge it. It hit her in the shoulder and she screamed again in pain.

There was a sudden, huge blast and a scream. Twilight was deafened by the noise.

Pinkie was gone, and the library was smouldering. Twilight moved painfully over to Spike, who was immersed in smoke. She saw the book she had been reading earlier.

...and the final kind, which only dragons approaching or at maturity may use. A blast of super heated air, powerfully heated by the natural magic in a dragon, that causes an explosion with only little fire...

"Good... job... Spike." Twilight said light headedly as she sank into unconsiousness.

Pinkie lay on the ground, just outside the library. Her body was burning with pain. She suspected she had broken some bones. She didn't know what had happened, but everything had turned white and painful suddenly and she was on the ground outside. She dreamily saw a white and blue shape leaning over her, and heard "Non, zis can't happen, not now..."

Then she too fell unconsious, just after she saw the shape above her collapse to it's knees and sigh.