minute prequel that  sets up events for the beginning of the fourth season. The first  scene occurs six months after the conclusion of Day 3 and shows  Driscoll firing Jack from CTU because of his drug use. The second  scene takes place three months before the events of Day 4 and shows  a terrorist sneaking across the U.S./Mexican border, and then  killing his accomplices. The third and final scene occurs six hours  before Day 4 begins and shows Jack and Audrey in a love scene. The  prequel is available on the Region One set, but not Region Two. See  "Season 4 Prequel."