A catastrophe has occurred. A new species of bee has a horrible venom, which alters the psyche, bringing out the most primal of instincts. These bees have been contained, yet most of Equestria has fallen to the sickness. Twilight Sparkle has found something that could lead to a cure, but she must find somepony to test it on.

A Stung - MLP crossover! If you haven't read the book Stung, I suggest you do! It'll help you understand the story.