Adventuring to the 30th century, a quick side trip turns grave as the Doctor and Derpy find themselves in the middle of mysterious earthquakes that only affect single buildings, and touchy robots with deadly tendencies. With the help of Luna herself, they set out to uncover the reasons behind these strange phenomena only to discover a plot against Canterlot itself. The TARDIS crew and Princess Luna must find a way to stop this mysterious mare before innocent lives are lost at the steel hooves of her robot army.