Twilight Sparkle's friends are all dead. She sets to work resurrecting them through forbidden black magic. The magic slowly turns her eyes red, and she forms the identity of Blood Star to try and separate herself from culpability for her actions.

Applejack is meant to be a bedsheet ghost clasping her hat in her hooves to identify herself, but a wardrobe malfunction backstage has left only her face hooded.

Pinkie has a physical form, but her mind seems very rattled, and the chains she wears seem to imply that something is trying to work against Blood Star from the other side.

Rarity's body gets dug up and her soul summoned into it, but strong hints are dropped that the soul inhabiting her body is not Rarity. She is the most vocal in her attempts to dissuade Blood Star.

Fluttershy is a fairly threadbare reanimation, barely more than a whisper of life hanging around in the pentagram. Most likely due to Blood Star being quite stressed during this particular summoning.

Rainbow Dash is pretty clearly a demon doing a poor masquerade.

The story's perspective never leaves the summoning circle. Offscreen, Twilight is falling under steadily more scrutiny for what she's done, especially from Celestia.

At the end, it is revealed that this was all a stage play put on for the yaks, written by yaks for yak audiences.

http://moderatelydeviant.deviantart.com/art/My-Little-Ghosties-Friendship-is-Necromancy-280348021