Tasked to find a cure for a new strain of the feather flu that causes pegasi to not be able to conceive, Twilight manages to make a potion, that, in theory, would boost the drinker's sperm count by a significant factor. As Twilight takes a shower to get ready for going out for dinner, Rarity walks inside Twilight's castle and discovers the potion on the coffee table, and thinking that Twilight has set tea out for her like she normally does with all of her guests, drinks it all due to her unquenchable thirst. As she feels her extremities start to tingle, she quickly discovers that it was not tea at all, and in turn, she becomes a he.

Contains: Genderswap, Estrus, a Sexy Spitfire, and... you know how things are gonna go.