"Supernatural" will reach its monumental 100th episode next week. To mark the occasion, The CW has been kind enough to share not only the preview but also three clips in advance.
Dean begins to think the only way to stop Lucifer is to say yes to Michael, but the angels decide they don't need him anymore. Dean, Sam and Castiel are horrified at the angels' new game plan and take on Zachariah to prevent an all out war on Earth. Meanwhile, a familiar face returns. According to EW's Michael Ausiello, the "familiar face" here is "someone you definitely thought was dead and gone forever."
In the first clip, Sam and Dean argue about Dean surrendering to Michael while in the second one Jim reminds Dean how he keeps himself alive based on a promise he made to Dean. In the third one, Castiel beats Dean to unconsciousness to stop the apocalypse.