We have the synopsis for the 300th episode of Supernatural!
 
SUPERNATURAL
“Lebanon”— (8:00-9:00 p.m. ET) (Content Rating TBD) (HDTV)
JEFFREY DEAN MORGAN RETURNS FOR THE 300TH EPISODE – Sam (Jared Padalecki) and Dean (Jensen Ackles) look to occult lore for a solution to their latest problem, but instead of a resolution, they find much more than either of them had anticipated. Jeffrey Dean Morgan (John Winchester) guest stars. The episode was directed by Robert Singer and written by Andrew Dabb & Meredith Glynn. (#1413). Original Airdate 2/7/2019.

Source:

The CW

 
See also Supernatural Episode 300 Makes the Cover of Entertainment Weekly SPOILERS  For more spoilers!
 
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