I was thinking of a situation where a group of teens, however many people (Maybe 4-5 at max), discover an artifact from an Equestrian time long past, it contains massive amounts of powerful magic, that in the wrong hooves or hands, can change the fabric of time and space. This group of kids ends up unlocking that artifact, and in the process, are changed into ponies. The amount of energy released when it occurred alerted nations around the world. Equestria received a beacon of some sort from the release of the magic, alerting them to the long lost treasure. The artifact was divided between the group of kids, but the former humans will have to find a way to access it and help themselves and Equestria from being destroyed in the search for great power.
I was planning for this to start on Earth and make its way over to Equestria, with Earth forces in tow soon after. Possibly after the group was captured by the government of whichever country that's decided, it's important which country is chosen because that way there will be a variety of how the group is treated, how the captors speak, and how everyone acts. The group will be saved by a one time effort by Celestia, Luna, or Twilight (Maybe all three, I haven't decided) and the government finds a way to open that same portal that was used to save the group to go after them with whatever the choose.
I sort of put out what came to mind, I like it, but I know it needs tuning.
So... Feedback?
I kind of messed up on the title, I was thinking something else when I wrote it and completely forgot to change it.