Derpy lives her life with her daughter Derpy in the town of ponyville, enjoying life as it is. But her job is dealing with a little bit of problems.

They get a letter from a frail old mare, the mailing adress being the everfree forest, and the resident being a manticore with the abilitiy to speak.

As others are unwilling Derpy volunteers to deliver the message, and this leads her to a responsibility she will never forget