After a time spell goes wrong, due to Spike's carelessness, Twilight finds herself in new Ponyville, and in a new role. Crime and murder rule the streets, magic is forbidden and her friends are in the line of fire. Only one with quick wit such as Twilight can solve the crimes, and find out what had happened to the magic she had grown accustomed to.

The stories are done in a episodic format, with one grand mystery arching over the whole series. Each episode is written as a diary post from Twilight herself.