A new alicorn has arrived in Ponyville. She seems to have many extrodinary but unrealistic abilities,
such as being able to change the force of gravity and bending fire.
Yet she has no cutie mark.
Twilight Sparkle has a very hard time believing that this pony is real.
The strange, talented pony, named Turquoise, for her fur color, seems like she's not a real pony, and gradually, Turquoise begins to be suspected by the citizens of Ponyville.
Twilight Sparkle eventually decides that Turquoise does not only have pony blood in her.
She may also be part of another species.