This takes place a short time after Discord was imprisoned.

Celestia, fearing she is no longer fit to rule her kingdom, releases Discord into Twilight Sparkle's care.

While poor Twilight is dealing with Discord and his shenanigans, Luna is trying to get to the bottom of Celestia's true reasons for freeing the spirit of chaos.

Note: I finished going over the first chapter with 6ix, and if my understanding is correct hes going to help me the best he can as I stumble along, helping fix the story while he teaches me better writing skills. (I think you should all go over to his page and spam him with thank you's!)