"What Is and What Should Never Be" is the twentieth episode of the paranormal drama television series Supernatural's second season. It was first broadcast on May 3, 2007 on The CW. The narrative follows series protagonist Dean Winchester (Jensen Ackles) who finds himself in an alternate reality after a confrontation with a djinn [sic]. The creature appears to have fulfilled Dean's greatest wish: that his mother had not been killed when he was a child. Dean is happy in the new world until it becomes apparent that his previous work as a hunter of supernatural creatures has been undone. At this point, he rejects the alternate reality, and attempts to find a method to bring himself back.