A simple sci-fi story. If you don't think Three-Body Problem is for you, come have a look here. A civilization's existence doesn't necessarily depend on itself; it may simply be needed by a far more powerful being. If one day you can return to your home, I hope you can do something for it, rather than being unable to think because your brain genes were altered, your thoughts locked, and your memories erased. Evil isn't caused by these vague, insubstantial things that have restricted you.