"Exposed" is the episode of UFO: The Series in which Colonel Paul Foster joins S.H.A.D.O. and in which singer-turned-actor Michael Billington joins the semi-regular cast of the series. Its focus is a paranoia about official government cover-ups of UFOs, and it deals with one pilot who is willing to risk everything to learn--and expose--the truth. But that ends up backfiring as, having found out too much, he finds himself essentially being drafted into a war.