It's the magical discovery of the millennium! Using a series of magical techniques devised by Starlight for leveraging limited magical power for greater effect, and a theory that Twilight quietly snuck out of the Forbidden Section with, a spell has been developed that can reverse Death itself!
There's just one problem: Ponyville doesn't exactly have a reputation for murders. They've tested the spell on a mouse, sure, but they've yet to find a dead pony who fits the requirements for the spell.
So Glimmer suggests that they make a dead pony. And, after racking their brains for a while, there's only one pony that both of them would willingly murder.
Written in a day under the influence of some very bad writing prompts.