This story is a sequel to Secrets of the Everfree
What happens when two sonic rainbooms are performed at EXACTLY the same time? Why, it creates a parallel universe, of course. Only, this is a universe where Acrylic never meets Torchwood. Therefore, the Seventh Element isn't formed, and worse, Charcoal Stormwood is never born to stop Chrysalis from invading Equestria. Yeah, things are pretty messed up.
Now, Ditzy and the Doctor have to get Acrylic and Torchwood to realize they have feelings for each other... and maybe discover such feelings for themselves. This should be good.
I HIGHLY reccomend reading the prequels first, considering that the alternate universe and characters are based off of the existing one. If you jump right in, you will be REALLY confused.