Supernatural will not air tonight, December 17, 2009, as the CW Network airs a special Vampire Diaries Marathon from Monday, December 14 through Friday, December 18 (8:00-10:00p.m. ET/PT).
Next week (December 24), the series will air a Season 3 episode, "A Very Supernatural Christmas."
Supernatural will return with new episodes on January 21, 2010.