Xenosaga: Pied Piper

Pied Piper is set a century before the events of Xenosaga Episode I; taking place 4000 years in the future, humanity has left Earth and established civilization in another part of the Milky Way galaxy under the rule of the Galaxy Federation. The story follows Federal Police Special Operations member Jan Sauer investigating a series of terrorist attacks on the Federation's hyperspace transport network U.M.N. (Wikipedia)