This story is a sequel to Memento Mori

Twilight learned a valuable lesson, long ago. Memento Mori: you too, will die. It was a bitter pill, but she accepted it and her boundless curiosity about the darkest of lores was for a while sated. But when she discovers a curious volume in the bottom of Ponyville library, hidden in the most unsuspecting of places (for after all, who would look in such a sleepy town?) she begins to feel a pull that she is not sure she wishes to resist.

(A sequel of sorts to Momento Mori, featured on EQD.)