A shocking twist from the fourth episode was the detonation of a suitcase nuke that killed twelve thousand civilians. The subsequent episodes, however, hardly showed any of the panic that would result from this. David Fury explained the development by saying that the intended writing direction kept fluctuating. "In the early seasons of 24, writers tried to map out stories and arc out stories a little bit more than they did, say, in seasons four and five, and four and five turned out to be two of most successful seasons." The nuclear threat was defused before the end of the season, leading to a story that was more personal for Jack. A panel of writers at Comic-Con said that they originally planned for Tony Almeida to return in the sixth-season finale.