"Dean was always going to end up in Heaven, and we were always going to see Sam's life in fast-forward," Dabb revealed online, explaining that the basic premise of the series finale remained the same.

Was supposed to be the series finale. Eric Kripke initially planned for Supernatural to be five seasons long. That is exactly why the episode is named "Swan Song" (goodbye) with a voice-over and flashbacks. But Sera Gamble, the new show-runner, took over penning it from season six and on.