Freedom is often taken for granted. It is only when you experience oppression fist-hand that its value starts to make itself clear. Whether you are a pony from the serene, peaceful land of Equestria, or a human from the seemingly free planet of Earth, liberty is never thought about until it is gone.
In a fictitious Earth, that's as brutal as our own, humans have finally been able to break through dimensional barriers, finding Eqeustria. But these scientists aren't instested solely in studying this newly-discovered world and its inhabitants. They aren't even for befriending the new species and making peace with them. No, they have something else planned, something more sinister and diabolical than any of that...slavery.
Source of photo: http://sultanknish.blogspot.com/2012/04/from-slavery-to-freedom.html