This story is a sequel to The Night Princess and the Day Job
Luna got a day job to help her better relate to the ponies of Equestria, and all was well. But when a niece she knows next to nothing about is getting married, the Princess of the Night offers to take a night shift at the StarsBucked near Canterlot University as a way of blowing off a little steam.
Pity it's the Night Shift of the Living Dead.
This piece is a sequel to The Night Princess and the Day Job, and should probably be read as such.