In COLONIZATION Mulder's search for the truth suddenly seems near its end when he and Scully meet Cassandra Spender. A multiple abductee, Cassandra believes that aliens came to Earth on a mission that has somehow gone terribly wrong. Her theory is confirmed when Krycek reveals that three abduction sites were beacons for alien colonization and the death and destruction at those sites were caused by a small alien rebel force. Determined to prevent the colonization of Earth, this force is also eliminating all proof that an alien presence was ever on the planet. Unfortunately for Mulder, his quest for the truth has made him part of the proof which must be eliminated.