Vicereine Puissance has ruled as one of Princess Luna's richest and most powerful nobles for fifty years, but not even her uncountable wealth or legions of followers can save her from old age. As her health begins to fail and the doctors tell her there is nothing they can do, she rejects the suggestion of Luna and others that she should retire and spend her remaining time with her family. Instead she decides to solve this problem as she has solved all others: by drawing upon her stupendous resources and vast political power in order to obtain the one remaining thing she wants: the immortal, ageless life of an alicorn. But while she thinks she can afford any price, the journey she sets out on could prove to be far more costly than she had ever anticipated.

Lunaverse story. Setup for Golden Horseshoes.